[QoL][QoC] Clean up CSS into modular structure

[gbowne1]

This PR:

• cleans up the monolithic style.css into multiple files and a css structure

• changes /src/css/style.css to app.css which gets script tag imported to index.html

This is;

• easier to maintain
• promote less CI issues with multiple contributors and collaborators
• easier to add new styles
• easier to read
• easier to debug style and layout issues by making it easier to narrow down conflicts

[gbowne1]

Ignore the CI failure here. This is WIP towards less failures.

[gbowne1]

Inline styles from;

• login.html
• register.html
• go-live.html
• watch.html

need to be added to /pages/ then linked in each page.

We should also consider some global styles and a mobile specific stylesheet at some point in the future

I would also recommend adding a bootstrap-override.css to house anything going against bootstrap 5.3's default styling.

[gbowne1]

Sorry for the large pile of commits, just showing work in progress here.

[Ved178]

Changes seem to work fine. Ready to merge.

[gbowne1]

This should be a lot easier to maintain with some minor tweaks.

Less likely two or more contributors will have to touch the same file.

Also, now we can easily fix issues and make a more robust css system.