Changelog category (leave one):

• Bug Fix (user-visible misbehavior in an official stable release)

Changelog entry (a user-readable short description of the changes that goes into CHANGELOG.md):

Fix recovering replicated databases when moving the metadata file takes a long time.

When creating a Replicated DB, at this point, the DB is considered started because the loading tasks are finished.
The DDLWorker can process the DDLs. If there is a create table DDL, it needs to acquire the table ddl_guard here. The ddl_guard requires the shared db mutex here.

If moving the metadata file takes a long time, the DB ddl_guard is still on hold. When DDLWorker is creating a table, it cannot acquire the DB shared mutex and throws an exception:

throw Exception(ErrorCodes::UNKNOWN_DATABASE, "Database {} is currently dropped or renamed", database_name);

This PR:

• When acquiring the DB lock fails, if the DB exists, retry with a timeout.
• Moves the moving file before checking if the table loading tasks are finished

Documentation entry for user-facing changes

• Documentation is written (mandatory for new features)