## Summary
- When a user already has a connection to a bank/provider, that
institution is now hidden from the list when they open the \"Connect
Bank\" dialog
- Applies to all providers: EnableBanking institutions (matched by
`aspsp_name`), Binance, Bitpanda, and Indexa Capital (matched by
`provider`)
- `ConnectAccountDialog` accepts a new `connections` prop (passed from
the connections settings page where it's already available);
`ConnectAccountInline` (used in onboarding) accepts an optional
`connections` prop defaulting to `[]`
## Tests
- Added 2 backend tests to `ConnectionControllerTest` verifying the data
contract: the connections page sends `provider` and `aspsp_name` fields
for all provider types, which the frontend filtering logic depends on
1058904b14