Add a button to check fee recipient of each validator

[Marketen]

To be considered, in "my validators" table, there could be a button to check the fee recipient of each validator. This button should be enabled even if the validator is subscribed already.

It could be used for users who want to doublecheck their fee recipient in each relay easily

[Marketen]

ultrasound has an implementation similar to this. We could do this but with all relays that the oracle operates with

Ideally, the call should be done from frontend to the relay endpoint directly like:
<RELAY_BASE_URL>/relay/v1/data/validator_registration?pubkey=<VAL_PUBKEY>
example:
https://boost-relay.flashbots.net/relay/v1/data/validator_registration?pubkey=0xaf294f5663defdba078e0c16b349952ab762f8019f42f45fc0a369666e12d836247e4d7a3e3bd564826dcffcfdc50114

If asking the relay directly is not possible (CORS could be an issue) we could ask the oracle (endpoint /registeredrelays/<VAL_PUBKEY>