Label filter bar test case error

[Arif-Khalid]

Describe the bug
One test case in label filter bar component tests describe the filter behaviour subject of filters service as undefined after the latest changes to filters service, keeping filters

To Reproduce
Steps to reproduce the behavior:

1. Go to label-filter-bar.component.spec.ts
2. Uncomment the test it (should update all labels with latest emitted value after ngAfterViewInit)
3. Run npm run test
4. See error of undefined value

Expected behavior
Filter$ in filters service should always be defined since it is given an initial value and is never overwritten.
There are no errors in full build

Desktop (please complete the following information):

• OS: Windows 11
• Browser OperaGX
• Version LVL5 (core: 107.0.5045.60)

Additional context
This issue only occurs after keeping filters PR #281