Add Mutesync dynamic update interval and catch invalid response values

[bramkragten]

Proposed change

This PR sets the update interval to 10 seconds by default, but to 1 second when in a meeting.

The client sometimes returns None, at least for muted, and this resulted in the binary_sensor going to off. We now throw when we get a None value during an update.

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)
• 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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Checklist

• The code change is tested and works locally.
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• Tests have been added to verify that the new code works.

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[probot-home-assistant]

Hey there @currentoor, mind taking a look at this pull request as its been labeled with an integration (mutesync) you are listed as a codeowner for? Thanks!
_{^{(message by CodeOwnersMention)}}

[MartinHjelmare]

Looks good!