We switched to the size-based load balancing, which now has more
strict requirements for load stats. We no longer need only per-node
stats, but also per-tablet stats.
Bootstrapping a node triggers stats refresh, but allocating tablets on
table creation didn't. So after creating a table, load balancer
couldn't make progress for up to 60s (stats refresh period).
This makes tests take longer, and can even cause failures if tests are
using a low-enough timeout.
Fixes https://github.com/scylladb/scylladb/issues/27921
No backport becuse only master is vulnerable (size-based load balancing).
Closesscylladb/scylladb#27926
* https://github.com/scylladb/scylladb:
test: cluster: Add reproducer for missed notification in topology coordinator
topology_coordinator: Wake up the state machine after stats refresh
topology_coordinator: Move tablet_load_stats_refresh_before_rebalancing injection earlier
topology_coordinator: Fix potential missed notification
topology_coordinator: Refresh load stats after table is created or altered
tablets: Do a group0 read barrier on tablet load stats refresh
topology_coordinator: Ensure stats are refreshed in the gossip scheduling group
test: Use ManagerClient.{disable,enable}_tablet_balancing()
test: Add missing calls to disable_tablet_balancing() in tests which use move_tablet() API
test: pylib: Introduce ManagerClient.{disable,enable}_tablet_balancing()
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