oidc: Inject currently hardcoded CLOUDRON_OIDC_PROVIDER_NAME env var

This is designed to be used in the packages for the login button:
"Login with ${CLOUDRON_OIDC_PROVIDER_NAME}"

src/services.js

@@ -2111,6 +2111,8 @@ async function getDynamicEnvironmentOidc(app, options) {
     tmp['CLOUDRON_OIDC_CLIENT_ID'] = client.id;
     tmp['CLOUDRON_OIDC_CLIENT_SECRET'] = client.secret;
 
+    tmp['CLOUDRON_OIDC_PROVIDER_NAME'] = 'Cloudron';
+
     return tmp;
 }