Add fingerprint to metabase

[christoph-maurer]

@simon-wacker Can I exchange

   mutation {
     sendKeys(input: {
       asciiArmoredKeys: <ASCII_ARMORED_KEYS>
       keyFingerprint: <SIGNING_KEY_FINGERPRINT>
     }) { }
   }

at

api/apis/database.graphql

Line 1578 in dacc9a9

asciiArmoredKeys: <ASCII_ARMORED_KEYS>

by

mutation {
  allowRepresentativeToSignData(
    input: {
      institutionId: <UUID_INSTITUTION>
      userId: <UUID_USER> 
    }
  ) {
    errors {
      code
      message
      path
    }
  addKeyFingerprint(
    input: { institutionId: <UUID_INSTITUTION>, keyFingerprint: <SIGNING_KEY_FINGERPRINT>, userId: <UUID_USER> }
  ) {
    keyFingerprint
  }
}

Then upload your public key to https://keys.openpgp.org/ with
`gpg --export <SIGNING_KEY_FINGERPRINT> | curl -T - https://keys.openpgp.org`
and verify your email address.

[simon-wacker]

No, because there are some changes needed to key handling in the metabase. I'm working on that right now. I've also started working on updating the approval documentation in database.graphql some months ago before the "keeping UUIDs in sync" task became more important.