Add UpCloud integration with account listing and details retrieval

Signed-off-by: Steven4Hooisma <112615049+Steven4Hooisma@users.noreply.github.com>

pkg/connector/provider/builtin.go

@@ -83,6 +83,7 @@ func NewBuiltinRegistry() *Registry {
 		supabaseRegistration(),
 		tailscaleRegistration(),
 		tallyRegistration(),
+		upcloudRegistration(),
 		vercelRegistration(),
 		yousignRegistration(),
 		zendeskRegistration(),