fix: wrap DCM project name in IDENTIFIER() for list/drop deployments

[sfc-gh-olorek]

Pre-review checklist

• I've confirmed that instructions included in README.md are still correct after my changes in the codebase.
• I've added or updated automated unit tests to verify correctness of my new code.
• I've added or updated integration tests to verify correctness of my new code.
• I've confirmed that my changes are working by executing CLI's commands manually on MacOS.
• I've confirmed that my changes are working by executing CLI's commands manually on Windows.
• I've confirmed that my changes are up-to-date with the target branch.
• I've described my changes in the release notes.
• I've described my changes in the section below.
• I've described my changes in the documentation.

Changes description

DCMProjectManager emits SQL for 10 DCM subcommands, but the project-name identifier was being injected two different ways:

• 8 methods use FQN.sql_identifier, which wraps the name in IDENTIFIER('<name>'). This is the conventional pattern across the CLI (see apps/manager.py's ALTER WORKSPACE {workspace_fqn.sql_identifier} call sites) and is the form used everywhere else in the DCM plugin: EXECUTE DCM PROJECT IDENTIFIER('<name>') DEPLOY/ANALYZE/PLAN/PREVIEW/REFRESH/PURGE/TEST, and CREATE DCM PROJECT IDENTIFIER('<name>').
• 2 methods — list_deployments and drop_deployment — were still using the raw FQN.identifier property, emitting SHOW DEPLOYMENTS IN DCM PROJECT <name> and ALTER DCM PROJECT <name> DROP DEPLOYMENT.

That inconsistency meant these two subcommands did not normalize fully-qualified / case-sensitive project names through the same IDENTIFIER(...) path that the rest of the manager (and the account-level session) relies on, producing different behaviour for the same FQN depending on which snow dcm subcommand the user ran.

This PR makes both call sites use project_identifier.sql_identifier, matching the other 8 sites and the parser-supported form (SHOW ... IN DCM PROJECT IDENTIFIER(:PROJ_NAME), ALTER DCM PROJECT <id> DROP DEPLOYMENT).

Testing

• Updated the two affected unit tests in tests/dcm/test_manager.py to assert on the new IDENTIFIER('my_project') wrapping.
• Full DCM unit suite (tests/dcm/) passes locally — 295 tests, 46 snapshots.