Web UI fix missing units psm2

[PhilippEngler]

Description

This PR will add the units (W) and the correct minimum and maximum values to the power threshold, lower threshold and higher threshold textboxes in the channel 7 for HmIP-PSM-2 and HmIP-PSM-2 QHJ devices.

Related Issue

This should solve #2746.

Types of changes

• Docs change / refactoring / dependency upgrade
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Alternate Designs

Possible Drawbacks

There might be a problem with the values. It could be that they require conversion (see #2746). During my tests, there was no need for conversion.

Verification Process

I have used the lower and higher values to values around the current power consumption. I have not run in any problems.

Release Notes

• Fixed an issue where incorrect min/max values and no units where displayed in channel 7 for HmIP-PSM-2 and HmIP-PSM-2 QHJ devices.

Contributing checklist

• My code follows the code style of this project.
• I have read the CONTRIBUTING and LICENSE document.
• I fully agree to distribute my changes under Apache 2.0 license.

[PhilippEngler]

@jens-maus: thank you and please excuse my mistake. I will be more careful next time.

[jens-maus]

No problem. The procedure how to create a proper WebUI patch is unfortunately quite cumbersome and also undocumented...