Authorized route migration for routes owned by security-threat-hunting (#198386)

### Authz API migration for authorized routes

This PR migrates `access:<privilege>` tags used in route definitions to
new security configuration.
Please refer to the documentation for more information: [Authorization
API](https://docs.elastic.dev/kibana-dev-docs/key-concepts/security-api-authorization)

### **Before migration:**
Access control tags were defined in the `options` object of the route:

```ts
router.get({
  path: '/api/path',
  options: {
    tags: ['access:<privilege_1>', 'access:<privilege_2>'],
  },
  ...
}, handler);
```

### **After migration:**
Tags have been replaced with the more robust
`security.authz.requiredPrivileges` field under `security`:

```ts
router.get({
  path: '/api/path',
  security: {
    authz: {
      requiredPrivileges: ['<privilege_1>', '<privilege_2>'],
    },
  },
  ...
}, handler);
```

### What to do next?
1. Review the changes in this PR.
2. You might need to update your tests to reflect the new security
configuration:
  - If you have tests that rely on checking `access` tags.
  - If you have snapshot tests that include the route definition.
- If you have FTR tests that rely on checking unauthorized error
message. The error message changed to also include missing privileges.

## Any questions?
If you have any questions or need help with API authorization, please
reach out to the `@elastic/kibana-security` team.

Co-authored-by: Angela Chuang <6295984+angorayc@users.noreply.github.com>

x-pack/plugins/security_solution/server/lib/siem_migrations/rules/api/create.ts

@@ -25,7 +25,11 @@ export const registerSiemRuleMigrationsCreateRoute = (
     .post({
       path: SIEM_RULE_MIGRATIONS_PATH,
       access: 'internal',
-      options: { tags: ['access:securitySolution'] },
+      security: {
+        authz: {
+          requiredPrivileges: ['securitySolution'],
+        },
+      },
     })
     .addVersion(
       {