ROX-24182: update workload CVE overview header

[dvail]

Description

Updates the Workload CVE page to have a more descriptive header above the table, and moves the Namespace View and Default filter buttons into this header.

Follow up

The NS view and Default Filter buttons should only be displayed for "Observed" - we need to remove them for Deferred and FP tabs. https://issues.redhat.com/browse/ROX-24318

Checklist

• Investigated and inspected CI test results
• Unit test and regression tests added
• Evaluated and added CHANGELOG entry if required
• Determined and documented upgrade steps
• Documented user facing changes (create PR based on openshift/openshift-docs and merge into rhacs-docs)

If any of these don't apply, please comment below.

Testing Performed

With CVEs:

Without CVEs:

Feature flag off:

[openshift-ci]

Skipping CI for Draft Pull Request.
If you want CI signal for your change, please convert it to an actual PR.
You can still manually trigger a test run with /test all

[rhacs-bot]

Images are ready for the commit at 59d6484.

To use with deploy scripts, first export MAIN_IMAGE_TAG=4.4.x-767-g59d6484dd1.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 47.97%. Comparing base (bf602fc) to head (59d6484).
Report is 1 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master   #11144   +/-   ##
=======================================
  Coverage   47.97%   47.97%           
=======================================
  Files        2330     2330           
  Lines      166667   166667           
=======================================
  Hits        79955    79955           
+ Misses      80362    80361    -1     
- Partials     6350     6351    +1     

Flag	Coverage Δ
go-unit-tests	47.97% <ø> (ø)

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[openshift-ci]

@dvail: The following test failed, say /retest to rerun all failed tests or /retest-required to rerun all mandatory failed tests:

Test name	Commit	Details	Required	Rerun command
ci/prow/ocp-4-15-ui-e2e-tests	59d6484	link	false	/test ocp-4-15-ui-e2e-tests

Full PR test history. Your PR dashboard.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository. I understand the commands that are listed here.

[dvail]

ocp-4-15 failure is an existing Config Management flake