Add framework for supporting other Fedi software

[ItsVipra]

Reasoning

Currently ProToots only supports Mastodon and (presumably) close forks. However Fedi is much more than Mastodon.
Different software uses different classnames etc., so a way to support those different platforms without trying everything in one messy block of code would be helpful.

[ItsVipra]

how fediact does it: https://github.com/Lartsch/FediAct/blob/main/src/inject.js#L6

[ItsVipra]

https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/Content_scripts#loading_content_scripts

Maybe have one content script that matches any site and calls a different script depending on which Fedi client we're on

Additionally, everything relating to fetching pronouns can be factored out into its own function

update: content_script does not have access to the scripting api
the procedure would have to be;

1. load content_script checksite.js
2. checksite.js sends message with site type to background script
3. background script calls main_$sitetype.js
4. proceed as normal
5. (communicate with fetchpronouns.js or import it?)

[ItsVipra]

closed thanks to #32