Add more paramaterization to the VSTS build template.
- Make the nuget restore operation paramertized.
- Make the core build operation paramertized.
- Correctly enquote parameters.
- [x] Add new vsts-pr pipeline for Pull Request Validation.
- [x] Repurpose vsts-ci for Continuous Intrgeation.
- [x] Add commented headers to the pipeline files.
No significant changes for vsts-rs and vsts-tt.
Avoid publishing artifacts during a CI build because the storage containers only allow for RS (authenticated) builds to publish artifacts.
Skipping the publishing step during CI builds will avoid the situation where a build result is reported as a partial success (build + test succeeded, but publish failed).
- [x] Restore the MicroBuild tasks.
- [x] Enable signing of artifacts.
The release build was somehow broken, this change should be sufficient to repair it.