Github actions for bun & playwright

For our opensource sveltekit cms project we need proper testing as they were started but dome incorrectly.

Fix the existing workflow for github to automate all Inkl creating npm / docker creation.

Tests needed all for main & next branch allowing also single manual tests

All existing tests need to be be adapted as code/ functions have changed. No security risks should be implement for api tests

Implement more test:
Setup (will change drastically soon to gui based )
/login with pw reset
/User edits & with token creation
Collection crud & collectionsbuilder
MediaGallery with media handeling
WidgetsManager
ThemeManager
Navigation

Create a mdx doc that explains our testing setup / procedure

Commit fix to next branch via pull request

SveltyCMS.com