Fix KeyError from zwave_js diagnostics

[kpine]

Proposed change

Fixes an issue when attempting to download the Device diagnostics for a Z-Wave JS Device. If one of the Device's entities has a missing primary value, a KeyError is raised and the file fails to download. This change prevents the error and allows the file to be downloaded as usual.

If the primary value is unknown, the "primary_value" in the diagnostic data is replaced with None, to signify the information is missing.

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 #
• This PR is related to issue: Z-Wave JS not reading thermostat air (current) temperature  #63255
• Link to documentation pull request:

I discovered this problem in my own production system while investigating the related issue.

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[probot-home-assistant]

Hey there @home-assistant/z-wave, mind taking a look at this pull request as it has been labeled with an integration (zwave_js) you are listed as a code owner for? Thanks!
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[MartinHjelmare]

When does this happen normally?

[kpine]

Reasons I can think of:

1. A driver update that removes previous functionality. This happened in the past with alarm level and type values, that were removed by the driver in favor of notification values.
2. A re-interview that failed. When you re-interview a device, the driver removes all of the values. If the interview fails in any way, the device still becomes ready but the previous values won't be recreated.
3. A firmware upgrade or device-reconfiguration, which could disable previous functionality (I have a rely that can change exposed sensors based on configuration). Upon re-interview, the values would be lost.

Case 1 is the problem in my production system, as mentioned in the linked issue. This sensor has been included since first using Z-Wave JS, and I've never pruned the entities.

Case 2 is likely the cause for another of my Zooz water sensors as some of their devices are known to have interview failures. I'm pretty sure I was re-interviewing nodes during testing, and this happened.

Also, I'm only using the "value removed" event to cause the problem in the test. In most real-life cases, it's just going to be the node state dump on connection is missing the value. I could also just delete the value directly from the Node instance, but manipulating these data structures directly doesn't seem to be common in the tests.

[MartinHjelmare]

Thanks!