feat: store user last accessed, and sshkey last used timestamps

[shreddedbacon]

General Checklist

• [ ] Affected Issues have been mentioned in the Closing issues section
• [ ] Documentation has been written/updated
• [ ] PR title is ready for inclusion in changelog

Database Migrations

• [ ] If your PR contains a database migation, it MUST be the latest in date order alphabetically

Whenever a user accesses the API update the last_accessed attribute on the user.

Alternative approach could be to store this in the API DB to reduce calls to keycloak though.

query allUsers {
  allUsers{
    email
    lastAccessed
  }
}
# result
{
  "data": {
    "allUsers": [
      {
        "email": "guest@example.com",
        "lastAccessed": "2024-03-12T00:14:32.000Z"
      }
    ]
  }
}

Also when the api/keys endpoint is hit, and a valid sshkey is detected, a new last_used field is updated to indicate when the key was last used.

      {
        "email": "maintainer@example.com",
        "lastAccessed": "2024-03-12T09:07:13.000",
        "sshKeys": [
          {
            "name": "maintainer-key",
            "lastUsed": "2024-03-12 09:06:07"
          }
        ]
      }

[shreddedbacon]

ssh-portal-api will either need to use the API, or be updated to include the function to update the last used timestamp when an ssh key is used

[smlx]

Should the SSH key last used also include the last time it was used to generate a token? From what I can tell this PR doesn't do that but I could be wrong.

[shreddedbacon]

Should the SSH key last used also include the last time it was used to generate a token? From what I can tell this PR doesn't do that but I could be wrong.

In the legacy SSH service, it is called whenever the authorize.sh script is called and hits the /keys endpoint in the API. So whenever a key is used and matches, it will get updated. Token, SSH, whatever.