Refactor libs into @umbraco-cms/backoffice/* (#608)

* merge libs rollup configs to one rollup

* move css from libs to src/core

* run rollup on cms build

* move test-utils to /utils folder

* move css to src/core

* mark @umbraco-cms/backoffice as external when building for CMS

* rename all models to include @umbraco-cms/backoffice in their path to allow us to publish as a single module

* rename all imports to @umbraco-cms/backoffice/*

* rename events to umb-events to avoid rollup error of protected module name(?)

* test that libs can build

* move css to src/core

* move umb-lit-element and modal elements to src/core

* move some modal interfaces back to libs/modal

* move the icon store into src/core since it is very localized to the backoffice

* comment out build:libs for now since Github runs out of memory

* rename to match tsconfig alias

* add package.json to libs

* only make libs for lib folders

* turn off emit for typescript since we are handling types for libs separately

* build libs locally

* add script to move libs to final destination with some transform

* move libs after build

* move package.json to dist folder first (so we can publish from there)

* remove inline comments

* ensure the outputDir exists

* Remove re-export of extensions-registry library from models library

* move to individual files to avoid circular imports

* check if outputDir exists before trying to create it

* write transforms first in dist file and then copy the file to outputDir

* ensure all umbraco types are external

* copy information from main package.json file

src/Umbraco.Web.UI.Client/.github/workflows/build_test.yml

@@ -34,6 +34,7 @@ jobs:
     - run: npm ci --no-audit --no-fund --prefer-offline
     - run: npm run lint
     - run: npm run build
+    # - run: npm run build:libs
     - run: sudo npx playwright install-deps
     - run: npm test
     - name: Upload Code Coverage reports