"PR create" should use default PR template

**Is your feature request related to a problem? Please describe.**
It is not possible to create a PR from CLI using PR templates. The PR template cannot be added after PR is created.

**Describe the solution you'd like**
The command "pr create" should respect default pull request template at least. It would be nice to have an option to use another template upon creation. Like:
"pr create --template "template.md"

**Additional context**
https://docs.microsoft.com/en-us/azure/devops/repos/git/pull-request-templates?view=azure-devops