various: change OAuth and WIF auth key resolvers to take struct args

Change signature of OAuth and identityfederation auth key resolution
hooks to take in structs instead of lists of args as they were getting
unwieldily.

Updates https://github.com/tailscale/tailscale/issues/20339

Signed-off-by: Mario Minardi <mario@tailscale.com>

tsnet/tsnet.go

@@ -1007,7 +1007,10 @@ func (s *Server) resolveAuthKey() (string, error) {
 		if authKey == "" {
 			clientSecret = s.getClientSecret()
 		}
-		authKey, err = resolveViaOAuth(s.shutdownCtx, clientSecret, s.AdvertiseTags)
+		authKey, err = resolveViaOAuth(s.shutdownCtx, tailscale.ResolveAuthKeyArgs{
+			AuthKey: clientSecret,
+			Tags:    s.AdvertiseTags,
+		})
 		if err != nil {
 			return "", err
 		}
@@ -1033,7 +1036,13 @@ func (s *Server) resolveAuthKey() (string, error) {
 				return "", fmt.Errorf("audience for workload identity federation found, but client ID is empty")
 			}
 		}
-		authKey, err = resolveViaWIF(s.shutdownCtx, s.getControlURL(), clientID, idToken, audience, s.AdvertiseTags)
+		authKey, err = resolveViaWIF(s.shutdownCtx, tailscale.ResolveAuthKeyWIFArgs{
+			BaseURL:  s.getControlURL(),
+			ClientID: clientID,
+			IDToken:  idToken,
+			Audience: audience,
+			Tags:     s.AdvertiseTags,
+		})
 		if err != nil {
 			return "", err
 		}