[Lens] Fix focus on ES|QL editor refresh

[walterra]

Summary

Follow up to #235372.

• The layer tabs include A11Y logic to focus on the layer config when the layer tabs change. This also triggers when mounting the layer panel. Because the ES|QL editor remounts this section on every refresh, it would move the focus to the layer config (away from the editor). This PR adds a fix to skip the focus logic when in ES|QL mode.
• Removes the unused language prop from FlyoutWrapperProps.
• Improves rerendering when there's just one layer and selectedLayerId hasn't been set yet.

Checklist

• [x] This was checked for breaking HTTP API changes, and any breaking changes have been approved by the breaking-change committee. The release_note:breaking label should be applied in these situations.

[elasticmachine]

Pinging @elastic/kibana-visualizations (Team:Visualizations)

[elasticmachine]

:green_heart: Build Succeeded

• Buildkite Build
• Commit: b9755377e883127c12a564ffd50dd00069bd12b4

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
lens	1.6MB	1.6MB	+127.0B

History

• :green_heart: Build #370365 succeeded 2a23b976b3afb8a14dc32c1ba1cdfa12a46483d1
• :green_heart: Build #369219 succeeded 122a9604e549a2cd094c32366bff1ae065994ac4
• :broken_heart: Build #369142 failed 0dc868eea8765de2fd2107d57c0b6806c46aedfa

cc @walterra