Add Metro message command unit tests

[ConnorQi01]

Summary

Add unit coverage for the ReloadApp and ShowDevMenu commands.

Proposed Changes

• Verify ReloadApp sends the reload message to Metro for the current project.
• Verify ShowDevMenu sends the devMenu message to Metro for the current project.
• Verify errors from sendMessageToMetro propagate through both commands.

Test Plan

• npx prettier --check test\extension\commands\reloadApp.test.ts test\extension\commands\showDevMenu.test.ts
• npm run build
• npm test - fails in an existing test: rn-extension commandsRegistered command list assertion. reloadAppCommand and showDevMenuCommand each ran 2 tests with 0 failures.

Closes #2793

[azure-pipelines]

Azure Pipelines:
There may be pipelines that require an authorized user to comment /azp run to run.

[ConnorQi01]

/azp run

[azure-pipelines]

Azure Pipelines:
Successfully started running 1 pipeline(s).
1 pipeline(s) were filtered out due to trigger conditions.