Add reload search analyzer, root and xpack API examples

[lcawl]

Relates to #2482

This PR copies examples from:

• https://www.elastic.co/guide/en/elasticsearch/reference/master/indices-reload-analyzers.html
• https://www.elastic.co/guide/en/elasticsearch/reference/master/rest-api-root.html
• https://www.elastic.co/guide/en/elasticsearch/reference/master/usage-api.html
• https://www.elastic.co/guide/en/elasticsearch/reference/master/info-api.html

It also edits some doc_id and ext_doc_id values based on https://www.elastic.co/guide/en/elasticsearch/reference/master/repositories-metering-apis.html

[github-actions]

Following you can find the validation results for the APIs you have changed.

API	Status	Request	Response
indices.reload_search_analyzers	🟢	2/2	2/2
nodes.clear_repositories_metering_archive	⚪	Missing test	Missing test
nodes.get_repositories_metering_info	⚪	Missing test	Missing test

You can validate these APIs yourself by using the make validate target.

[github-actions]

Following you can find the validation results for the APIs you have changed.

API	Status	Request	Response
indices.reload_search_analyzers	🟢	2/2	2/2
info	🟢	6/6	6/6
nodes.clear_repositories_metering_archive	⚪	Missing test	Missing test
nodes.get_repositories_metering_info	⚪	Missing test	Missing test

You can validate these APIs yourself by using the make validate target.

[github-actions]

Following you can find the validation results for the APIs you have changed.

API	Status	Request	Response
indices.reload_search_analyzers	🟢	2/2	2/2
info	🟢	6/6	6/6
nodes.clear_repositories_metering_archive	⚪	Missing test	Missing test
nodes.get_repositories_metering_info	⚪	Missing test	Missing test

You can validate these APIs yourself by using the make validate target.

[github-actions]

Following you can find the validation results for the APIs you have changed.

API	Status	Request	Response
indices.reload_search_analyzers	🟢	2/2	2/2
info	🟢	6/6	6/6
nodes.clear_repositories_metering_archive	⚪	Missing test	Missing test
nodes.get_repositories_metering_info	⚪	Missing test	Missing test

You can validate these APIs yourself by using the make validate target.