Rewrite resolveprojectreferences MSBuild calls to reduce the amount of batching done

[baronfel]

Context

When writing microsoft/vstest#15295, @rainersigwald pointed out to me that we suffer from the same anti-pattern with regards to usage of the MSBuild Task in ResolveProjectReferences, which is a very-commonly-called Target.

When batching is used directly in the MSBuild Task call, it can lead to repeated invocations of the Task, which have small but noticeable overheads. The fix is to push as much information about the customization of the individual Project builds being requested as possible into the Item descriptions of the projects themselves - we do this by precomputing a few item lists, one for each MSBuild call section.

This may increase overall memory usage, so it's worth measuring against the reduction in overhead from the batched Task calls. In my investigations of a recent partner team build, it's very common to end up with at least 2 batches per logical Task request in this particular Target:

Changes Made

Precompute Project Item lists for each of the three steps of ResolveProjectReference:

• GetTargetPath
• default or explicitly-specified build targets
• GetNativeManifest

Testing

None additional, as this should be a not-publicly-visible change.

Notes