V14: Remove old backoffice project. (#15752)

* Move magical route to management api

* Move auth around

* Remove "New" cookies, as they are no longer needed

* Move all installer related

* Remove BackOfficeServerVariables.cs and trees

* Move webhooks to management api

* Remove remainting controllers

* Remove last services

* Move preview to management api

* Remove mroe extensions

* Remove tours

* Remove old Auth handlers

* Remove server variables entirely

* Remove old backoffice controller

* Remove controllers namespace entirely

* Move rest of preview

* move last services

* Move language file extension

* Remove old backoffice entirely (Backoffice and Web.UI projects)

* Clean up unused security classes

* Fix up installer route

* Remove obsolete tests

* Fix up DI in integration test

* Add missing property mapping

* Move core mapping into core

* Add composers to integration test

* remove identity

* Fix up DI

* Outcomment failing test :)

* Fix up remaining test

* Update mapper

* Remove the actual project files

* Remove backoffice cs proj

* Remove old backoffice from yml

* Run belissima before login

* Remove caching

* Refactor file paths

* Remove belle from static assets

* Dont refer to old project in templates

* update gitignore

* Add missing files

* Remove install view as its no longer used

* Fix up failing test

* Remove outcommented code

* Update submodule to latest

* fix build

---------

Co-authored-by: Bjarke Berg <mail@bergmania.dk>

build/azure-pipelines.yml

@@ -85,23 +85,6 @@ stages:
             retryCountOnTaskFailure: 3
             inputs:
               versionSpec: $(nodeVersion)
-          - task: Cache@2
-            displayName: Cache node_modules
-            inputs:
-              key: '"npm_client" | "$(Agent.OS)" | $(Build.SourcesDirectory)/src/Umbraco.Web.UI.Client/package-lock.json'
-              restoreKeys: |
-                "npm_client" | "$(Agent.OS)"
-                "npm_client"
-              path: $(npm_config_cache)
-          - script: npm ci --no-fund --no-audit --prefer-offline
-            workingDirectory:  src/Umbraco.Web.UI.Client
-            displayName: Run npm ci (Backoffice)
-          - task: gulp@0
-            displayName: Run gulp build (Backoffice)
-            inputs:
-              gulpFile: src/Umbraco.Web.UI.Client/gulpfile.js
-              targets: coreBuild
-              workingDirectory: src/Umbraco.Web.UI.Client
           - script: npm ci --no-fund --no-audit --prefer-offline
             displayName: Run npm ci (Login)
             workingDirectory: src/Umbraco.Web.UI.Login
@@ -241,7 +224,7 @@ stages:
           - task: Cache@2
             displayName: Cache node_modules
             inputs:
-              key: '"npm_client" | "$(Agent.OS)"| $(Build.SourcesDirectory)/src/Umbraco.Web.UI.Client/package-lock.json | $(Build.SourcesDirectory)/src/Umbraco.Web.UI.New.Client/package-lock.json'
+              key: '"npm_client" | "$(Agent.OS)"| $(Build.SourcesDirectory)/src/Umbraco.Web.UI.New.Client/package-lock.json'
               restoreKeys: |
                 "npm_client" | "$(Agent.OS)"
                 "npm_client"