Notification resolution bug

[OlgaIvkovic]

Description

• Fixed issue of not being able to resolve notification due to an empty text
• Added validation checks against only white spaces in both text and resolution message

Solves issue: #950

Pre-review checks

Please ensure to do as many of the following checks as possible, before asking for committer review:

• DEPENDENCIES are up-to-date. Dash license tool. Committers can open IP issues for restricted libs.
• Copyright and license header are present on all affected files
• If helm chart has been changed, the chart version has been bumped to either next major, minor or patch level (compared to released chart).

[tom-rm-meyer-ISST]

Thanks for fixing! LGTM! Noticed #953 during test.

Sidenote: Following conventional commit you don't need to specify the empty brackets if you don't specify a scope.