[TRACKER] Check application to use a `admin` scope if using the AdminAPI

See !1643 (comment 40174)

This is just a grep '###' docs/clients.md | sed -e 's/###/- [ ]/' so most are probably non-applicable.

Pleroma clients:

• MastoFE ( !2256 (merged) )
• Pleroma-FE
• AdminFE

Third-party clients:

• Roma for Desktop: N/A
• Social: N/A
• Whalebird: N/A
• Amaroq: N/A
• Fedilab: Seems applicable
• Nekonium: Seems N/A
• Roma iOS: N/A
• Roma android: N/A
• Tusky: Seems N/A
• Twidere Android: N/A
• Twidere iOS: N/A
• Brutaldon: Maybe?
• Feather: N/A
• Halcyon: Seems N/A
• Pinafore: N/A
• Sengi: N/A
• Kyclos: N/A