Custom vite builder

[LukasKlement]

The default vite application builder of Angular does not support plugins. Similar to custom-webpack, it would be great to be able to support adding plugins to the build process using vite.

See someone else requesting it in the angular-cli repo: angular/angular-cli#26329
Another request: angular/angular-cli#26859

[just-jeb]

There is an ongoing work on supporting extension for esbuild builder, this should also support plugins for Vite dev-server.