* oh boy we're doing some testing

* Set up fake filesystem, add test for PublishFlatContainer

* SigningInformation test

* remove net test sdk

* re-rename for merge

* Changes resulting from merge to master

* smoe more updates

* re-add generatebuildmanifest.proj

* quick fixups

* Some refactoring based on discussions of how to implement this better :)

* Got the abstract class in a good state; started refactoring classes so they can be dependency injected

* Tests work now

* Pulled Nunit stuff out of the test project since we're not using it

* missing namespaces were causing the build to fail

* Added more DI to the places that needed it. Fixed a couple of failing tests

* Injecting the TaskLoggingHelper into it's dependencies instead of manually passing it into methods

* Missed a couple places that needed the logger DI

* commenting all the things

* Tests to ensure DI was properly wired up for the refactored tasks

* Tests to ensure top-level dependencies are configured

* Fixing failing tests

* Attempting to fix Nuget error

* trying to suss out the nuget error

* trying to suss out the nuget error

* putting everything back the way it was

* checking to see if I can't reference the VersionTools.Task project for tests

* Let's see if this fixed the tests

* skip signing of testing project

* Omitting more test projects from being signed

* reverting changes to skip signing on test projects. Need a different solution

* Need to set up FluentAssertions to be signed by the third party cert

* Does Helix like strings that were once XDocuments better?

* Figure out why the task is failing on Helix

* Changed save options for ToString-ing XML to improve test reliability

* let's see if we can get error messages out of the Build Engine

* adding some logging to figure out why PackageArtifactModelFactory is failing

* Making the file path strings OS-agnostic

* Consolidated expected content builders into reusable functionality

* Created factory for VersionsRepoUpdater classes, attempting to abstract away some of the DI

* clean up random stuff that was added to the csproj files

Co-authored-by: Jon Fortescue <jofortes@microsoft.com>