Improve first line indent

[vkbo]

Summary:

This PR:

• Fixes an issue with first line indent after comments.
• Adds settings to customise how the first line indent works,
• Moves the first line indent settings to the Format tab so it can be applied to more than just ODT documents.

Related Issue(s):

Closes #1852

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