feat(server): runtime setting support (#5602)

---

<details open="true"><summary>Generated summary (powered by <a href="https://app.graphite.dev">Graphite</a>)</summary>

> ## TL;DR
> This pull request adds a new migration file, a new model, and new modules related to runtime settings. It also introduces a new `Runtime` service that allows getting, setting, and updating runtime configurations.
>
> ## What changed
> - Added a new migration file `migration.sql` that creates a table called `application_settings` with columns `key` and `value`.
> - Added a new model `ApplicationSetting` with properties `key` and `value`.
> - Added a new module `RuntimeSettingModule` that exports the `Runtime` service.
> - Added a new service `Runtime` that provides methods for getting, setting, and updating runtime configurations.
> - Modified the `app.module.ts` file to import the `RuntimeSettingModule`.
> - Modified the `index.ts` file in the `fundamentals` directory to export the `Runtime` service.
> - Added a new file `def.ts` in the `runtime` directory that defines the runtime configurations and provides a default implementation.
> - Added a new file `service.ts` in the `runtime` directory that implements the `Runtime` service.
>
> ## How to test
> 1. Run the migration script to create the `application_settings` table.
> 2. Use the `Runtime` service to get, set, and update runtime configurations.
> 3. Verify that the runtime configurations are stored correctly in the database and can be retrieved and modified using the `Runtime` service.
>
> ## Why make this change
> This change introduces a new feature related to runtime settings. The `Runtime` service allows the application to dynamically manage and modify runtime configurations without requiring a restart. This provides flexibility and allows for easier customization and configuration of the application.
</details>

packages/backend/server/tests/config.spec.ts

@@ -1,14 +1,13 @@
-import { Test, TestingModule } from '@nestjs/testing';
+import { TestingModule } from '@nestjs/testing';
 import test from 'ava';
 
 import { Config, ConfigModule } from '../src/fundamentals/config';
+import { createTestingModule } from './utils';
 
 let config: Config;
 let module: TestingModule;
 test.beforeEach(async () => {
-  module = await Test.createTestingModule({
-    imports: [ConfigModule.forRoot()],
-  }).compile();
+  module = await createTestingModule();
   config = module.get(Config);
 });
 
@@ -17,19 +16,21 @@ test.afterEach.always(async () => {
 });
 
 test('should be able to get config', t => {
-  t.true(typeof config.host === 'string');
+  t.true(typeof config.server.host === 'string');
   t.is(config.NODE_ENV, 'test');
 });
 
 test('should be able to override config', async t => {
-  const module = await Test.createTestingModule({
+  const module = await createTestingModule({
     imports: [
       ConfigModule.forRoot({
-        host: 'testing',
+        server: {
+          host: 'testing',
+        },
       }),
     ],
-  }).compile();
+  });
   const config = module.get(Config);
 
-  t.is(config.host, 'testing');
+  t.is(config.server.host, 'testing');
 });