[Visualizations] Make visualization saved object share-capable and remove savedVisLoader

[VladLasitsa]

Summary

Removed old savedVisLoader completely and did
Step 4 of https://www.elastic.co/guide/en/kibana/master/sharing-saved-objects.html#sharing-saved-objects-step-4

[jportner]

Similar to #114408 (comment), the Spaces API integration tests are failing because they use test fixtures for pre-8.0 visualizations, but they skip the index migration process. I can update the test data accordingly, I'll push a commit to this PR to do so.

[jportner]

The last API integration tests (for upsert) are failing because of a bug, this PR will be unblocked by #114929

[jportner]

@elasticmachine merge upstream

[elasticmachine]

Pinging @elastic/kibana-vis-editors (Team:VisEditors)

[jportner]

The Spaces test changes that I made LGTM, obviously 😄

[kibanamachine]

💚 Build Succeeded

• continuous-integration/kibana-ci/pull-request
• Commit: ad9e5b5
• Storybooks Preview
• Documentation Changes

Metrics [docs]

Module Count

Fewer modules leads to a faster build time

id	before	after	diff
visualizations	108	104	-4

Public APIs missing comments

Total count of every public API that lacks a comment. Target amount is 0. Run node scripts/build_api_docs --plugin [yourplugin] --stats comments for more detailed information.

id	before	after	diff
visualizations	286	285	-1

Async chunks

Total size of all lazy-loaded chunks that will be downloaded as the user navigates the app

id	before	after	diff
visualizations	72.8KB	72.8KB	-3.0B

Public APIs missing exports

Total count of every type that is part of your API that should be exported but is not. This will cause broken links in the API documentation system. Target amount is 0. Run node scripts/build_api_docs --plugin [yourplugin] --stats exports for more detailed information.

id	before	after	diff
visualizations	16	15	-1

Page load bundle

Size of the bundles that are downloaded on every page load. Target size is below 100kb

id	before	after	diff
visualizations	38.8KB	36.1KB	-2.7KB

Unknown metric groups

API count

id	before	after	diff
visualizations	304	303	-1

References to deprecated APIs

id	before	after	diff
visualizations	100	81	-19

History

• 💚 Build #161369 succeeded 6f7b3c4
• 💔 Build #160578 failed a267889
• 💔 Build #160421 failed 067dba6
• 💔 Build #160410 failed eb6392d
• 💔 Build #160403 failed 1ab7da4

To update your PR or re-run it, just comment with:
@elasticmachine merge upstream

cc @VladLasitsa

[flash1293]

Tested and works as expected, LGTM

[kibanamachine]

Friendly reminder: Looks like this PR hasn’t been backported yet.
To create backports run node scripts/backport --pr 114620 or prevent reminders by adding the backport:skip label.