refactor(resharding): migrate replication to api/task

[meskill]

Migrate the replication process to task:

• separate the logic into nested tasks: ReplicationTask -> ReplicationClusterTask -> ReplicationShardTask with separate state and tracking
• extend the definitions and statuses used to display progress and send to EE
• rip apart most of the orchestrator and publisher

[codecov]

Codecov Report

❌ Patch coverage is 93.25221% with 122 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
pgdog-stats/src/resharding.rs	21.05%	30 Missing ⚠️
pgdog/src/api/replication.rs	93.97%	27 Missing ⚠️
pgdog/src/backend/replication/tests.rs	87.85%	26 Missing ⚠️
...eplication/logical/publisher/replication_stream.rs	94.66%	22 Missing ⚠️
pgdog-stats/src/task/replication.rs	76.92%	6 Missing ⚠️
.../src/backend/replication/logical/publisher/slot.rs	86.11%	5 Missing ⚠️
...nd/replication/logical/publisher/cutover_policy.rs	99.22%	2 Missing ⚠️
pgdog-stats/src/task/schema_sync.rs	96.96%	1 Missing ⚠️
...nd/replication/logical/publisher/publisher_impl.rs	96.96%	1 Missing ⚠️
...lication/logical/publisher/replication_progress.rs	99.23%	1 Missing ⚠️
... and 1 more

📢 Thoughts on this report? Let us know!

[levkk]

cool cool cool cool