Feat vs Anno Tab Labels Readability Fix (Cleaner Files)

[SudeepMangam]

Description:
In the Feat vs Ammo tab, the plot runs into problems relating to the labels. The X and Y axis are often clustered with too many labels causing the text to overlap. This causes the text to be unreadable for both the X and Y axis. As a result, the plot fails to communicate essential data when used for analysis.

Requirements:
OS: Ubuntu via WSL on Windows 11
Python Version: 3.9.13 (Miniconda)
Project Directory: ~/root/summer2025/SPAC_Shiny
Conda Environment: spacy_viz_py3913_wsl
Launch Command: python -m shiny run --reload app:app
Branch: Used the keyerror-fix branch
Dataset Used: Custom .h5ad file

Implementation:
This pull request addresses overlapping labels in the "Feat vs Anno" heatmap by introducing layout improvements to enhance readability regarding the overlap. Specifically:

Introducing a Font Size Slider to adjust the fonts of both the X and Y axis
Added an Abbreviate toggle that uses a dropdown slider to specify the length of the Abbreviation to the user
Created a Y axis label rotator, similar to that of the already implemented X axis label rotator
Formatted the markdowns for the Denograms so that the markdowns don't interfere with the Abbreviation's markdowns
These updates streamline user interpretation and make the visualization more accessible across various dataset scales.

[SudeepMangam]

Hi all,
I’d really appreciate it if you could take a look at this PR when you have a moment. I’m keen to hear your thoughts and make any necessary changes.