[Synonyms UI] Add Synonyms Set Detail UI

[efegurkan]

Summary

Adds route and table for the synonyms set detail page.
Actions are not implemented yet, whole plugin is behind feature flags. Another PR will add them following this.

Checklist

Check the PR satisfies following conditions.

Reviewers should verify this PR satisfies this list as well.

• Any text added follows EUI's writing guidelines, uses sentence case text and includes i18n support
• Unit or functional tests were updated or added to match the most common scenarios
• Flaky Test Runner was used on any tests changed
• The PR description includes the appropriate Release Notes section, and the correct release_note:* label is applied per the guidelines

[elasticmachine]

💚 Build Succeeded

• Buildkite Build
• Commit: c6a5a54

Metrics [docs]

Module Count

Fewer modules leads to a faster build time

id	before	after	diff
searchSynonyms	101	104	+3

Async chunks

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

id	before	after	diff
searchSynonyms	43.6KB	45.9KB	+2.3KB

Page load bundle

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

id	before	after	diff
searchSynonyms	4.4KB	4.7KB	+329.0B