Features/uuidv5

[jessehouwing]

Auto-generates a UUID for build tasks to enable dev & prod in the same environment

---

This change is 

[olandese]

Review status: all files reviewed at latest revision, all discussions resolved.

---

Comments from Reviewable

[jessehouwing]

@willsmythe @wpschaub This is a special case, resurrected from an old branch.

We have a couple of large clients who have a single VSTS account with links to a whole bunch of Azure resources. They are developing custom azure build and release tasks and want to publish experimental versions of an existing task to the same VSTS account. By default, this is prevented, as the taskIds aren't unique.

This version will enable extension builders to generate a unique task ID using the PublisherID, ExtensionID and TaskName.

I've tested these changes against my personal VSTS account already and it seems to work without issues.

Feedback welcome.

[mpseidel]

I would totally use this. We are also testing extensions in different versions in our account and have to take extra steps to make sure the task guids are unique acress extension versions.