Use version range on project references

[ronaldbarendse]

Prerequisites

• I have added steps to test this contribution in the description below

Description

When the current solution gets packaged (using dotnet pack), all project references will be converted to package dependencies that only specify the minimum version, for example: Umbraco.Cms 12.1.1 depends on Umbraco.Cms.Targets >= 12.1.1. This allows other dependencies to (accidentally) update any of the transitive Umbraco dependencies to a next major version, which will most likely cause compilation or (worst-case) runtime errors.

This can be prevented by setting the maximum version to the next major version as version range. Because the version is automatically generated and dependencies are specified in ProjectReferences, this version range must be dynamically set as well (better support for this has already been requested on the NuGet issue tracker). This PR contains an MSBuild target that updates the generated project reference version to use a version range, so when packaging version 12.1.0--rc.preview.96.gfec51a9, the dependency version is automatically updated to [12.1.0--rc.preview.96.gfec51a9, 13).

Testing can be done by verifying whether the Umbraco dependencies in the NuGet packages contain the version range, either by inspecting the build artifacts or running dotnet pack -c Release -o build.out locally.