Improved service default settings handling

[avoitenko-logitech]

Description

Improved service default settings handling

Motivation and Context

Previously used approach was frustrating for user Settings window allowed to edit and apply settings while option 'Use service default settings' was enabled. But with this option enabled setting values are ignored and overridden by values from service.json inside OBS. So now we fetch service default settings, present them to user and disable editing (or setting upper bound) for a certain settings.

How Has This Been Tested?

Tested by QA

Types of changes

• New feature (non-breaking change which adds functionality)