Fix email translationPath and docu

[kobergj]

Fixes custom translation path feature for notifications service and corrects its documentation.

[mmattel]

@kobergj grep -rn LC_MESSAGES in the services folder returns results in:
activitylog, userlog, notifications and graph.
Means that the change you made here possibly belongs also to the other services than notifocations.
I may be wrong though...

[kobergj]

@mmattel no. Other services work properly. Only notifications service had the issue

[mmattel]

@mmattel no. Other services work properly. Only notifications service had the issue

Got it.
Beside technical, this then should be consistent to avoid confusion service_name.po. Just my 2c

[sonarcloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
50.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud