[backend/frontend] Adding feature flag

[Dimfacion]

Proposed changes

• Adding feature flag

Related issues

Checklist

• [x] I consider the submitted work as finished
• [x] I tested the code for its functionality
• [ ] I wrote test cases for the relevant uses case
• [ ] I added/update the relevant documentation (either on github or on notion)
• [ ] Where necessary I refactored code to improve the overall quality

Further comments

This is based on OpenCTI implementation : https://github.com/OpenCTI-Platform/opencti/blob/8160869e99f4eb0ed56801ab9d9565027e553f4d/opencti-platform/opencti-graphql/src/config/conf.js#L479

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 0% with 4 lines in your changes missing coverage. Please review.

Project coverage is 25.79%. Comparing base (004e85a) to head (e529a78).

Files	Patch %	Lines
...enbas/rest/settings/response/PlatformSettings.java	0.00%	2 Missing :warning:
...va/io/openbas/service/PlatformSettingsService.java	0.00%	2 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #1070 +/- ## ============================================ + Coverage 25.50% 25.79% +0.28% - Complexity 1008 1012 +4 ============================================ Files 461 461 Lines 10785 10789 +4 Branches 526 527 +1 ============================================ + Hits 2751 2783 +32 + Misses 7968 7940 -28 Partials 66 66 ```

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.