Updates to web Dockerfiles to support microsoft/dotnet:2.1-sdk

- Dockerfiles changes
- Minor csproj updates to bring back "dotnet bundle" cli
- Enable all protocols in SignalR
- Update package-lock.json in spa

Remove explicitly copied dependencies, copy entire solution
into the conainter and depends on the cache to reduce build
time.

Addd temporary solution file which does not contains the
dcproj file to work around the issue that the dotnet cli
cannot handle dcproj.

1. Changes the build context of all services to the root level to be
able to access the dependencies for each project.
2. Commented out the prepublish scripts, these steps are moved into the
Dockerfile

Did not change any script yet, need help to identify what scripts we
need to change.

Lots of things to address yet, because nuget packages are still on 1.1

docker-use-platform creates mark file

Fixes #51

Everything works as exepcted except SPA version which need further adjustments