Novel tree meta data

[vkbo]

Summary:

This PR:

• Adds an arrow button behind each novel tree item that when clicked will generate a tool tip with all meta data from the index about an entry in the novel tree.
• Adds highlighting of the novel tree entries that belong to the document open in the editor.
• Enables uniform item height for Project Tree, Novel Tree and Outline.
• Enables auto-expanding items during drag and drop for the Project Tree.
• Enables all column focus highlighting for the Project Tree and Novel Tree.
• Removes the tree column width settings for the Novel and Project Tree in the main config,

Related Issue(s):

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