TypeScript Migration and various smaller QOL changes

[GreenMan36]

This pull request includes various changes made to migrate to TypeScript and improve the DX, enhance code quality.
Below are the highlights of the changes made:

Enhancements:

• Converted most of the extension to TypeScript for better type checking and autocompletion.
• Introduced itadButton, itadContainer, ItadItemInfo and ItadInlineIcon as pseudo components.
• Added a debounce for better performance on modern framework based websites.

Cleanup:

• Moved generic functions to utils.ts.
• Removed unnecessary const's boolean and a unneeded regex match.
• Renamed most of the main functions to make their use clearer.

Other changes:

• Updated README and manifest.
• Prioritized price/percentage in the element append function.
• Introduced a hardcoded blacklist for now to mitigate extension issues on problementic sites.

Please review and provide feedback.

There are still a lot of changes planned. However this is already quite a big change so I wish to have this merged so there's a good and agreed upon base to continue working on.

[tfedor]

This is now merged to develop, I'm not sure how to correctly set it up in GitHub so it shows as merged (should have changed base before merging in, my bad).