Make built-in code server setup more stable

[juliushaertl]

Best to be reviewed as individual commits for the frontend, backend changes are mostly moving code and adding proper status codes

• chore: Refactor frontend capabilities to a service to be able to update on the fly
• fix: Move auto setup of built-in code server to an async request done by the frontend
• Add typescript support for eslint and fix errors

Can be tested with:

• occ app:enable richdocumentscode
• occ config:app:delete richdocuments wopi_url
• Reload the file list
• Now a request happens that autoconfigures the built-in code server (if you are admin and it is not configured yet)
• Once succeeded it will update the capabilities in the frontend which makes the viewer work

Fixes #1282

[elzody]

Looks good other than the error

Property oc_isadmin does not exist on type Window & typeof globalThis

Not sure about it

[juliushaertl]

Fixed, I missed to add the types file for those