chore(31835): Add matrix-based Cypress job and Code Coverage

[vanch3d]

See https://hivemq.kanbanize.com/ctrl_board/57/cards/31835/details/

The Pr improves the CI pipeline for the frontend in two directions

• The Cypress-based tests (component and E2E) have been split into subgroups. to parallelise their execution through github action matrix. The splits are only actionable based on test file paths (i.e. globs) and are only viable because of an opinionated structure of the code base (e.g. E2E, extensions, components, modules). This reorganisation has reduced the duration of the CI pipeline by more than 60%
• Code coverage for the frontend is added, with integration with SonarQube Cloud (see https://sonarcloud.io/organizations/hivemq/projects)
  The integration relies on a local SonarQube configuration and on the extraction of the code coverage data for three sources of tests (unit tests with Vitest, component and E2E tests with Cypress, as organised into multiple tests).

The PR also refactors the frontend workflow to abide by the new Check structure imposed by #938:

• Files renamed
• Frontend workflow trigger changed to workflow_call
• Failure on final check removed fo frontend

Out-of-scope

• Integration of the frontend as a project in SonarQube cloud still needs to be configured properly. It will be done in a follow-up ticket.
• The visual tests (Percy) are not integrated anymore in the new frontend. It will be redone in a subsequent ticket

Before

After

After rebase

[oli-hivemq]

great setup!

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

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

See analysis details on SonarQube Cloud