* Add private setters for "from" and "to"
Add private setters for the "from" and "to" values in `AudioFileProcessorWaveView`. When being used the setters will ensure that the bounds are respected.
Also add a `range` method because this computation was done repeatedly throughout the code.
Fixes#7068 but masks some of the original problems with the code that computes out-of-bounds values for "from" and "to" like the `slide` method. Problematic code can still be found by temporarily adding the following assertions to the setters:
* `assert (to <= m_sample->sampleSize());` in `setTo`
* `assert (from >= 0);` in `setFrom`
* Remove superfluous calls to qMax and qMin
## Extract views
Extract the classes `AudioFileProcessorWaveView` and `AudioFileProcessorView` into their own files.
Reformat the new classes by removing unnecessary whitespace and underscores. Add spaces to if-statements.
Cleanup the includes.
## Remove friend relationship
Remove the friend relationship between `AudioFileProcessor` and `AudioFileProcessorView`.
Introduce getters for entities that the view is interested in.
