Fix build formatting and font handling

[vkbo]

Summary:

This PR:

• Makes the line break setting available as a general format option for manuscript builds.
• Adds new icons to font and quote selector buttons.
• Changes the Tokenizer to use a QFont instead of text/number settings.
• Updates font handling in HTML output.
• Updates font handling in ODT output.
• Adds an option to use Qt's font dialog, which has more options at least on Gnome desktop.

Related Issue(s):

Related to #1733

Reviewer's Checklist:

• The header of all files contain a reference to the repository license
• The overall test coverage is increased or remains the same as before
• All tests are passing
• All flake8 checks are passing and the style guide is followed
• Documentation (as docstrings) is complete and understandable
• Only files that have been actively changed are committed