Feature/dotnet7 migration (#828)

* migration to .net 7

* remove temp memory database

* adapt global.json .net 7

* adapt Rich Code Navigation to .net 7

* update and clean run for .net 7

* update .net ef tool

Co-authored-by: cedri <cedri@BAS>

.github/workflows/dotnetcore.yml

@@ -12,7 +12,7 @@ jobs:
     - name: Setup .NET
       uses: actions/setup-dotnet@v1
       with:
-        dotnet-version: '6.0.x'
+        dotnet-version: '7.0.x'
         include-prerelease: true
 
     - name: Build with dotnet