[homematic] Smaller fixes and conversion of properties files to UTF-8 (#10813)

[homematic] Smaller fixes and conversion of properties files to UTF-8 (#10813)

* Prevent possible NPE

Signed-off-by: Martin Herbst <develop@mherbst.de>
* Spotless

Signed-off-by: Martin Herbst <develop@mherbst.de>
* Fixes missing unit information (especially for HmIP devices)

For some HmIP devices the "valueunit" attribute is empty and thus no
default unit type could be derived. Using the data point name solves
this problem (at least for the relevant data points).

Fixes #10533

Signed-off-by: Martin Herbst <develop@mherbst.de>
* Condition result was wrong because of missing brackets

Signed-off-by: Martin Herbst <develop@mherbst.de>
* Regenerated and reorganized descriptions

Signed-off-by: Martin Herbst <develop@mherbst.de>
* Encoding changed to UTF-8 and some smaller text corrections

Signed-off-by: Martin Herbst <develop@mherbst.de>
* Use default value as maximum if is greater than received max value

For some devices the data point definition retrieved from the CCU
contains default values that are higher than the maximum value. In order
to allow the configuration of these config options the allowed maximum
value needs to be set to the default value.

Fixes #10552

Signed-off-by: Martin Herbst <develop@mherbst.de>