Resourceadm: refactor resourceadm Playwright test

[mgunnerud]

Description

Refactor validate resource Playwright test so it can be run multiple times without recreating the resources repo each time the test is run. The test has some conditions to prevent it from failing the second time it is run, and to prevent it from adding a new policy rule each time it is run.

Related Issue(s)

• this PR

Verification

• [ ] Your code builds clean without any errors or warnings
• [ ] Manual testing done (required)
• [ ] Relevant automated test added (if you find this hard, leave it and we'll help out)

Documentation

• [ ] User documentation is updated with a separate linked PR in altinn-studio-docs. (if applicable)