Updates in preparation for PR pipeline

[JimSuplizio]

These are eng changes being made in preparation for the PR pipeline. These changes do not affect anything other than the PR pipeline. These were originally tested in a PR made against the pipelinev3 branch and additional runs were made against the refs/merge of the PR.

• java - pullrequest pipeline ran correctly with these changes.
• java - core - ci run running against the refs/merge pipelinev3 PR.
• java - template - ci run running against the refs/merge of the pipelinev3 PR.

The changes are as follows:

1. I moved the save-package-properties into generate-project-list-and-cache-maven-repository.yml. Every job in the pipeline calls this, from build to analyze to tests. The choice here was either make everything wait for the build job and pull its artifacts or move the call here which computes the project list based upon the contents of the PR. Being that the computation takes like 25-30 seconds, this was better than making things wait on the build job. This did require plumbing the ServiceDirectory and ExcludePaths through to the template.
2. ci.tests.yml and initialize-test-environment.yml both needed the ServiceDirectory and ExcludePaths plumbed through because of generate-project-list-and-cache-maven-repository.yml
3. Stage-MavenPackageArtifacts.ps1 and Verify-Required-Maven-Artifacts.ps1 needed to be able to get the Artifacts lists from the PackageInfo directory if there was no Artifacts list passed in. The changes in both were relatively simple, if Artifacts weren't passed in then check the PackageInfo and produce the artifacts list from that. The rest of the processing is the same. The only difference here is that, for the staging, we don't know what the release artifacts list is, it'll copy all of the artifacts built as part of the PR. Being that this is a PR build, I don't see a problem there.
4. eng/pipelines/templates/jobs/ci.yml - In the case of the PR pipeline, call verify-readmes.yml instead of verify-readme.yml. For the verify-samples.yml, get the service directory list from the diff.json's ChangedServices, create a comma separated list and pass that through the ServiceDirectories template argument.

The primary reason to get this into main is that these are changes that shouldn't affect anything existing.

[JimSuplizio]

@weshaggard, as per our discussion, I've created an issue to track the changes requested in your comments.