refactor: remove systems default filter

[Dugowitch]

Description

Associated Jira ticket: HMS-11196

There was a backend filter that the frontend filter counteracted. The backend filter was removed, the FE filter can now be removed as well. The BE now returns both fresh and stale systems by default.

Side effect of not having default filters: 'Reset filters' becomes 'Clear filters'.

How to test the PR

Please include steps to test your PR.

Before the change

After the change

Checklist:

• The commit message has the Jira ticket linked
• PR has a short description
• Screenshots before and after the change are added
• Tests for the changes have been added
• README.md is updated if necessary
• Needs additional dependent work

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 77.38%. Comparing base (dfb1045) to head (8b7b32a).

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1763      +/-   ##
==========================================
- Coverage   77.41%   77.38%   -0.04%     
==========================================
  Files         102      102              
  Lines        3286     3286              
  Branches      756      752       -4     
==========================================
- Hits         2544     2543       -1     
- Misses        663      664       +1     
  Partials       79       79              

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