Currently only one global topology request (such as truncate, cdc repair, cleanup and alter table) can be pending. If one is already pending others will be rejected with an error. This is not very user friendly, so this series introduces a queue of global requests which allows queuing many global topology requests simultaneously.
Fixes: #16822
No need to backport since this is a new feature.
Closesscylladb/scylladb#24293
* https://github.com/scylladb/scylladb:
topology coordinator: simplify truncate handling in case request queue feature is disable
topology coordinator: fix indentation after the previous patch
topology coordinator: allow running multiple global commands in parallel
topology coordinator: Implement global topology request queue
topology coordinator: Do not cancel global requests in cancel_all_requests
topology coordinator: store request type for each global command
topology request: make it possible to hold global request types in request_type field
topology coordinator: move alter table global request parameters into topology_request table
topology coordinator: move cleanup global command to report completion through topology_request table
topology coordinator: no need to create updates vector explicitly
topology coordinator: use topology_request_tracking_mutation_builder::done() instead of open code it
topology coordinator: handle error during new_cdc_generation command processing
topology coordinator: remove unneeded semicolon
topology coordinator: fix indentation after the last commit
topology coordinator: move new_cdc_generation topology request to use topology_request table for completion
gms/feature_service: add TOPOLOGY_GLOBAL_REQUEST_QUEUE feature flag
6489308ebc