Install workload manifests in sdk band version derived from the (#81461)

Install workload manifests in sdk band version derived from the (#81461)

.. installer version.

- This is only for running Wasm.Build.Tests

Two new properties are added:

- `SdkBandVersionForWorkload_ComputedFromInstaller`: this is based on the
version derived from `dotnet --version`. `8.0.0-alpha.1.1234.1` becomes
`8.0.0-alpha.1`, and is used as the path where the manifests get installed for testing:
`sdk-manifests/$(SdkBandVersionForWorkload_ComputedFromInstaller)`

- `SdkBandVersionForWorkload_FromRuntimeVersions`: this is the version
band used for the packages generated. And simply rename of the earlier
`$(SdkBandVersionForWorkload)`.