Implement SavedObject Migrations v2

[joshdover]

Implement the new algorithm outlined in this RFC: #66056

• Implement new algorithm Resilient saved object migration algorithm #78413
• User-facing documentation User-facing documentation for resilient saved object migrations #86315
• QA Test plan Test plan for SavedObject Migrations v2 #84141
• The ElasticsearchClient should not log error messages for expected error responses from Elasticsearch. The new algorithm creates a lot of conflict errors that can safely be ignored, so if we don't silence these logs it creates a lot of unnecessary noise which can be misleading ElasticsearchClient should allow plugins to opt out of error logging #84447
• Debug log all saved object types and their latest migration versions Debug logging listing all saved object types with their migration versions #86320
• EsArchiver/FTR support for the new migration algorithm Unrevert "Migrations v2: don't auto-create indices + FTR/esArchiver support (#85778)" #89992
• Exit with a fatal error if a corrupt saved object is encountered v2 migrations should exit process on corrupt saved object document #91465

For 7.13+:

• Has the new algorithm achieved the outcome we wanted? Yes, we've seen a 10x decrease in the number of failed migrations.
• (after we verified that the outcome was achieved) Remove v1 migrations [Core] Remove v1 migrations #96396
• Support re-writing _id's for sharing across multiple spaces v2 migrations needs to support re-writing document _id's to support saved-objects in multiple spaces #86247
• Cleanup migrated docs on OUTDATED_DOCUMENTS_SEARCH step Cleanup migrated docs on OUTDATED_DOCUMENTS_SEARCH step #97965
• Collect and log all objects that fail to transform instead of failing the migration on the first document transform failure Saved object migrations: collect all documents that fail to transform instead of stopping the migration on the first failure #90279
• Add automated test for several Kibana instances running migrations in parallel Add an integration test for several Kibana instances performing migration in parallel #97975
• Cleanup Migrations v2 implementation Break up Migrations v2 Implementation into multiple files #99479
• Use named arguments Use named arguments in Migration actions #99242
• Enhance saved objects migrations collect failing docs implementation Enhance saved objects migrations collect failing docs implementation #99685

Future problems:

• Too many saved objects [Discuss] Too many saved-objects + migrations == 💥 #92933

[elasticmachine]

Pinging @elastic/kibana-platform (Team:Platform)

[pgayvallet]

All subtasks have been completed and we have another meta issue for the future enhancements. Let's close this one.