[Global Search] Fix case sensitivity tag search

[rshen91]

Summary

Closes https://github.com/elastic/kibana/issues/85584 and https://github.com/elastic/kibana/issues/85189

Tags cannot be created that are the same name, even if uppercase or lowercase. This PR fixes the issue where global search did not recognize tag:U vs tag:u and will provide suggestions if either uppercase or lower case tag name is provided.

Checklist

Delete any items that are not applicable to this PR.

• [x] Unit or functional tests were updated or added to match the most common scenarios

[elasticmachine]

Pinging @elastic/appex-sharedux (Team:SharedUX)

[kibana-ci]

:green_heart: Build Succeeded

• Buildkite Build
• Commit: 4ad85fa9b374ce2154b37e69f0417e727e85152a

Metrics [docs]

Page load bundle

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

id	before	after	diff
globalSearchBar	28.3KB	28.4KB	+104.0B

History

• :green_heart: Build #209539 succeeded e0b0ee3ece2d2dcc9eac58f502fc188111758748
• :green_heart: Build #209241 succeeded 2f75714aa454970fd480296bbee46e726b83f9b8
• :broken_heart: Build #209193 failed b58873a2a7305a54d937e5d2209a69af903af1ea

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

cc @rshen91