Rewrite of the UI using Typescript, Vue3, Windicss and Vite. The design should be close to the current one with some changes:
- latest pipeline in a sidebar on the right
- secrets and registry as part of the repo-settings (secrets and registry entries shouldn't be used as much so they can be "hidden" under settings IMO)
- start page shows list of active repositories with button to enable / add new ones (currently you see all repositories and in most cases you only add new repositories once in a while)
This is a preparation for #245 and adds a new endpoint (`.js``file) which can be included by the web-ui to get some config and credentials like the user profile or access-token.
By adding a new ENV variable called `WOODPECKER_WWW_PROXY` it is possible to serve a webinterface via a proxy configured by the `WOODPECKER_WWW_PROXY` value for development instead of serving the interface from the bundled code or from some folder location as the old `WOODPECKER_WWW` option allowed. Using a proxy allows developing the UI with hot-reloading.
