**Add approved & assigned issue number here:**
Resolves#2549
## Description:
Themes are purely for the client's rendering, and the server doesn't
need context on them. This PR moves `Theme.ts` from
`src/core/configuration` to `src/client/theme` and moves affiliation
colors to `render-settings.json`.
This is to support the ability to add additional themes more quickly,
such as colorblind-friendly themes. No visible changes occur from this
refactor.
## Please complete the following:
- [X] I have added screenshots for all UI updates
- [X] I process any text displayed to the user through translateText()
and I've added it to the en.json file
- [X] I have added relevant tests to the test directory
## Please put your Discord username so you can be contacted if a bug or
regression is found:
jetaviz
---------
Co-authored-by: Josh Harris <josh@wickedsick.com>
noahschmal