[discover] Extract discover grid flyout from discover grid component

[mattkime]

Summary

Extract discover grid flyout from discover grid component. Part of effort to turn discover into set of components consumable by other kibana apps.

Closes #144154

[elasticmachine]

Pinging @elastic/kibana-data-discovery (Team:DataDiscovery)

[kertal]

LGTM 👍 , it's much simpler than expected, which is : great! just added an suggestion to further simplify the code. Tested locally and works as expected

[kibana-ci]

💚 Build Succeeded

• Buildkite Build
• Commit: b404d67

Metrics [docs]

Async chunks

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

id	before	after	diff
discover	418.1KB	418.4KB	+233.0B

Unknown metric groups

ESLint disabled in files

id	before	after	diff
osquery	1	2	+1

ESLint disabled line counts

id	before	after	diff
enterpriseSearch	19	21	+2
fleet	61	67	+6
osquery	109	115	+6
securitySolution	440	446	+6
total			+20

Total ESLint disabled count

id	before	after	diff
enterpriseSearch	20	22	+2
fleet	70	76	+6
osquery	110	117	+7
securitySolution	517	523	+6
total			+21

History

• 💚 Build #95265 succeeded ebe18ef
• 💚 Build #95259 succeeded 787dc0e
• 💚 Build #95244 succeeded 6d9bdd4
• 💔 Build #94229 failed df06ddb
• 💔 Build #94227 failed 9fdbea6
• 💔 Build #94223 failed dbdabc3

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