Improve testability of installation code by refactoring it to completely
separate the GUI and non-GUI code, and to provide more robust support
for non-GUI access to some type of Addon Manager activity.
For users with git and GitPython installed, a new button is added to the
details view allowing them to change the branch they are on. Some other
minor UI changes are made to accomodate this new behavior.
Rather than manually parsing the output from the repo's host, the Addon Manager
now uses an embedded QWebEngineView to display the README data. This makes the
display more repo-location agnostic (rather than trying to parse the specific
code from GitHub, Gitlab, etc.). Special handling of known hosts is still
provided to improve the display of the page, but it is not required. Clicking a
link on the page still loads in a new system browser window, with the exception
of links to the FreeCAD wiki, which are loaded in the same browser. This is
expected to be used primarily to access traslated pages for Macros, so no
advanced web-browsing features are displayed (e.g. back buttons, history
access, etc.).
pylupdate does not extract translations when f-strings are used for the
translated text, so all f-strings are migrated to calls to format().
Several other minor translation issues are also addressed.
NOTE: This code has been run through the Black reformatter, which adds
trailing commas in many places that the stock Qt 5.x pylupdate does not
recognize. This code must be processed with the corrected pylupdate to
generate the correct translations.
Migrate to a UI that looks more like other software package managers, giving
more space to each addon by hiding the list when an addon is selected, and
providing a "back" button to get back.
Implements a two-style view option for the list of addons: expanded and
condensed, via a delegate that provides the drawing function for each row in
the table based on two different widget designs.
