[7.x] [core.metrics] Add support for multiple processes in ops metrics & stats API; deprecate process field (#109820)

[kibanamachine]

Backports the following commits to 7.x:

• [core.metrics] Add support for multiple processes in ops metrics & stats API; deprecate process field ([core.metrics] Add support for multiple processes in ops metrics & stats API; deprecate process field #109820)

[kibanamachine]

💚 Build Succeeded

• continuous-integration/kibana-ci/pull-request
• Commit: 5776cb8
• Storybooks Preview

Metrics [docs]

Public APIs missing comments

Total count of every public API that lacks a comment. Target amount is 0. Run node scripts/build_api_docs --plugin [yourplugin] --stats comments for more detailed information.

id	before	after	diff
core	998	1007	+9

Unknown metric groups

API count

id	before	after	diff
core	2251	2267	+16

References to deprecated APIs

id	before	after	diff
kibanaUsageCollection	0	1	+1
monitoring	1	2	+1
total			+2

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

cc @Bamieh