Move text direction styles

[jon-kirwan]

What

https://trello.com/c/fc41oyEK/1923-enable-individual-loading-of-stylesheets-in-government-frontend

Group document type text direction page styles in the application stylesheet as a pre-requisite to implementing the AssetHelper to load component and view style sheets only required on the page being viewed.

Why

• Currently, text direction styles are in individual style sheets, for each document type, and often no more than around 4 or 5 lines of CSS (see below). These styles should be grouped together in the application style sheet alongside similar print styles

.speech {
  .direction-rtl & {
    direction: rtl;
    text-align: start;
  }
}

• Also, in this case text compression increases the size of the asset. For example, for Case studies (_case-studies.css) from 132 bytes to 1.6 kb. Typically, this happens when the asset is very small and the overhead of the GZIP dictionary is higher than the compression savings, or when the resource is already well compressed. See https://web.dev/optimizing-content-efficiency-optimize-encoding-and-transfer/

Visual changes

None

Anything else

• Set up gem so stylesheets can be loaded individually govuk_publishing_components#3014
• Set up individual component CSS loading frontend#3342
• Set up individual component CSS loading smart-answers#6213
• RFC #149

[MartinJJones]

Looks good, nice work! 👍