Move the API setting out of the main extension

[upkarlidder]

Is your feature request related to a problem? Please describe.
The API URL section is a user setting and will most likely not change once initially set. However, the user still might want to change it to point to the development version of the API.

Describe the solution you'd like
Move this setting to the extension setting page as described here - https://developer.chrome.com/docs/extensions/mv3/options/

[github-actions]

👋 Hi! This issue has been marked stale due to inactivity. If no further activity occurs, it will automatically be closed in 14 days.

[akshaymattoo]

@upkarlidder I can take this issue. Let me know if someone is already not working on it. Thanks

[github-actions]

👋 Hi! This issue has been marked stale due to inactivity. If no further activity occurs, it will automatically be closed in 14 days.