Intialize mqtt lock in an unknown state in pessimistic mode

[jbouwh]

Breaking change

An MQTT lock with a configured state topic will initialize with state unknown instead of state unlocked unless the lock is set to optimistic mode. MQTT locks set to optimistic mode will still be initialized with state unlocked. Users should check if their automations are affected.

Proposed change

Intialize mqtt lock as unknown in pessimistic mode. An mqtt lock should be be initialized in an unknown state. This PR corrects that.

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New integration (thank you!)
• New feature (which adds functionality to an existing integration)
• Deprecation (breaking change to happen in the future)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Additional information

• This PR fixes or closes issue: fixes #
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[home-assistant]

Hey there @emontnemery, mind taking a look at this pull request as it has been labeled with an integration (mqtt) you are listed as a code owner for? Thanks!

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[emontnemery]

LGTM, thanks @jbouwh 👍