fixing issues when there is no initial data

[fungame2270]

Issue

Closes #141 .

Reason for this change

the change was made so the backend dont throw 404 when list is empty causing frontend to crash

Description of changes

this change makes that when get all groups or monitor the response is 200 with empty list. some tweaks done to groups repository to better return what is expected

Description of how you validated changes

tested locally

Checklist

• [X] I have tested my changes locally.
• [ ] I have updated the documentation to reflect my changes.
• [ ] I have added/updated unit tests (if applicable).
• [X] My code adheres to the CONTRIBUTING GUIDE

Aditional Information

[sonarcloud[bot]]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud

[sonarcloud[bot]]

Quality Gate passed

Issues
1 New issue
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud