Standardise and improve text fields

[joemull]

Is your feature request related to a problem? Please describe.
Janeway does not offer a consistent user interface for editing rich text fields. Early implementations used JQTE, and later ones use Summernote.

Describe the solution you'd like
I can see two viable options:

• Move all the JQTE fields to Summernote
• Move all the JQTE and Summernote fields to CKEditor

Whichever one is implemented, we should also review the use of bleach and make sure it's put on former JQTE fields.

Additional context

• CKEditor first mentioned four years ago: Use a WYSIWYG editor that allows easy relative links #1028
• Bleach #2282
• Auto-remove erroneous formatting for abstracts in metadata #1481
• Custom submission fields allow rich-text values but don't render the HTML #2670

[joemull]

When implementing this, see the discussion on PR #3983.

After #3983, we will just need to take care of the remaining places we use JQTE and Summernote:

rg jqte -g '!js' -g '!scss' -g '!css' > places_we_still_use_jqte.txt

src/core/homepage_elements/preprints/templates/preprints.html:    {% include "elements/jqte.html" %}
src/core/homepage_elements/about/templates/about_settings.html:{% include "elements/jqte.html" %}
src/core/homepage_elements/html/templates/html_settings.html:    {% include "elements/jqte.html" %}
src/templates/common/elements/edit_profile_js_block.html:{% include "elements/jqte.html" %}
src/templates/admin/install/journal.html:{% include "elements/jqte.html" %}
src/templates/admin/repository/notification.html:    {% include "elements/jqte.html" %}
src/themes/OLH/templates/elements/jqte.html:<script type="text/javascript">$("textarea").jqte();</script>
src/templates/admin/repository/review/notify_reviewer.html:    {% include "admin/elements/jqte.html" %}
src/templates/admin/copyediting/editor_review.html:    {% include "elements/jqte.html" %}
src/templates/admin/submission/submit_funding.html:    {% include "admin/elements/jqte.html" %}
src/templates/admin/production/assign_typesetter.html:    {% include "elements/jqte.html" %}
src/templates/admin/copyediting/do_copyedit.html:{% include "elements/jqte.html" %}
src/templates/admin/elements/jqte.html:<script type="text/javascript">$("textarea").jqte();</script>
src/templates/admin/production/notify_typesetter.html:	{% include "elements/jqte.html" %}
src/templates/admin/elements/review/draft_decisions_js.html:                    $("#id_email_message").jqteVal(data.decision_text)
src/templates/admin/elements/review/draft_decisions_js.html:            $("#id_email_message").jqteVal('')
src/templates/admin/copyediting/author_review.html:    {% include "elements/jqte.html" %}
src/templates/admin/copyediting/edit_assignment.html:    {% include "elements/jqte.html" %}
src/templates/admin/copyediting/add_copyeditor_assignment.html:    {% include "elements/jqte.html" %}
src/templates/admin/production/typeset_task.html:    {% include "elements/jqte.html" %}
src/templates/admin/production/assigned_article.html:    {% include "elements/jqte.html" %}
src/templates/admin/production/edit_typesetter_assignment.html:    {% include "elements/jqte.html" %}
src/templates/admin/proofing/request_typesetting_changes.html:    {% include "elements/jqte.html" %}
src/templates/admin/review/draft_decision.html:    {% include "admin/elements/jqte.html" %}
src/templates/admin/proofing/proofing_article.html:    {% include "elements/jqte.html" %}
src/templates/admin/proofing/notify_typesetter_changes.html:	{% include "elements/jqte.html" %}
src/templates/admin/proofing/notify_proofreader.html:	{% include "elements/jqte.html" %}
src/templates/admin/review/suggest_reviewers.html:{% include "elements/jqte.html" %}
src/templates/admin/proofing/edit_proofing_assignment.html:    {% include "elements/jqte.html" %}
src/templates/admin/review/reset.html:    {% include "elements/jqte.html" %}
src/templates/admin/proofing/do_proofing.html:    {% include "elements/jqte.html" %}
src/templates/admin/review/revision/view_revision.html:{% include "elements/jqte.html" %}
src/templates/admin/review/revision/edit_revision_request.html:    {% include "elements/jqte.html" %}
src/templates/admin/review/send_review_reminder.html:    {% include "elements/jqte.html" %}
src/templates/admin/review/revision/request_revisions.html:    {% include "elements/jqte.html" %}
src/templates/admin/proofing/acknowledge.html:	{% include "elements/jqte.html" %}
src/templates/admin/proofing/complete_proofing.html:    {% include "elements/jqte.html" %}
src/templates/admin/review/revision/request_revisions_notification.html:{% include "elements/jqte.html" %}
src/templates/admin/proofing/typesetting/typesetting_corrections.html:    {% include "elements/jqte.html" %}
src/templates/admin/cron/create_template.html:{% include "admin/elements/jqte.html" %}
src/templates/admin/press/merge_users.html:    {% include "elements/jqte.html" %}

rg summernote

docs/source/changelog.rst:* Ignore empty p and br tags from empty summernote fields by @joemull in https://github.com/BirkbeckCTP/janeway/pull/2714
requirements.txt:django-summernote==0.8.20.0
src/core/janeway_global_settings.py:    'django_summernote',
src/core/janeway_global_settings.py:    'summernote': {
src/core/janeway_global_settings.py:        # https://summernote.org/deep-dive/#custom-toolbar-popover
src/core/homepage_elements/journals_and_html/forms.py:from django_summernote.widgets import SummernoteWidget
src/core/middleware.py:                'django_summernote-editor', 'django_summernote-upload_attachment', 'cms_index', 'cms_page_new',
src/core/urls.py:    path('summernote/', include('django_summernote.urls')),
src/comms/forms.py:from django_summernote.widgets import SummernoteWidget
src/books/forms.py:from django_summernote.widgets import SummernoteWidget
src/static/admin/css/admin.css:.summernote-div {
src/press/admin.py:from django_summernote.admin import SummernoteModelAdmin