Fixes the following issues:
* fixes CLI berombau LucaMarconato
* fixes display of points and circles LucaMarconato
* fixes issue with name reinitialization tothmarcella
* revert to use PyQt5 melonora
* RGB/RGBA correctly displayed for 3/4 channel images rahulbshrestha
* layer visibility changes when changing coordinate system melonora
* fixes performance with multiscale images LucaMarconato
* refactor internal code to prepare for future refactoring melonora
Thanks to the reviewers giovp timtreis kevinyamauchi and the users that reported bugs.