This is a manual backport of #22452
Truncate table for tablets is implemented as a global topology operation. However, it does not have a transition state associated with it, and performs the truncate logic in topology_coordinator::handle_global_request() while topology::tstate remains empty. This creates problems because topology::is_busy() uses transition_state to determine if the topology state machine is busy, and will return false even though a truncate operation is ongoing.
This change introduces a new topology transition topology::transition_state::truncate_table and moves the truncate logic to a new method topology_coordinator::handle_truncate_table(). This method is now called as a handler of the truncate_table transition state instead of a handler of the truncate_table global topology request.
Fixes#22552Closesscylladb/scylladb#22557
* github.com:scylladb/scylladb:
truncate: trigger truncate logic from transition state instead of global request handler
truncate: add truncate_table transition state
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