feat(server): support installable license (#12181)

<!-- This is an auto-generated comment: release notes by coderabbit.ai -->
## Summary by CodeRabbit

- **New Features**
  - Added support for installing self-hosted team licenses via encrypted license files.
  - Introduced a new "Onetime" license variant for self-hosted environments.
  - Added a GraphQL mutation to upload and install license files.
  - License details now display the license variant.

- **Bug Fixes**
  - Improved error messages for license activation and expiration, including dynamic reasons.

- **Localization**
  - Updated and improved license-related error messages for better clarity.

- **Tests**
  - Added comprehensive end-to-end tests for license installation scenarios.

- **Chores**
  - Enhanced environment variable handling and public key management for license verification.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

packages/backend/server/src/base/error/def.ts

@@ -811,18 +811,17 @@ export const USER_FRIENDLY_ERRORS = {
   },
   invalid_license_to_activate: {
     type: 'bad_request',
-    message: 'Invalid license to activate.',
+    args: { reason: 'string' },
+    message: ({ reason }) => `Invalid license to activate. ${reason}`,
   },
   invalid_license_update_params: {
     type: 'invalid_input',
     args: { reason: 'string' },
     message: ({ reason }) => `Invalid license update params. ${reason}`,
   },
-  workspace_members_exceed_limit_to_downgrade: {
+  license_expired: {
     type: 'bad_request',
-    args: { limit: 'number' },
-    message: ({ limit }) =>
-      `You cannot downgrade the workspace from team workspace because there are more than ${limit} members that are currently active.`,
+    message: 'License has expired.',
   },
 
   // version errors