Add opt-in to always prompt for repo for issue creation and add comment to issue file specifying the repo

[mikeseese]

This PR adds a githubIssues.alwaysPromptForNewIssueRepo config variable that defaults to false. When set to true, if the user creates a new issue via the + button in the side panel, the extensions will always prompt the user for a repo to create the issue for instead of using the current open file. Behavior should not change for creating issues from selection/etc that are supposed to be directly contextual.

This PR also adds a comment in the NewIssue.md file telling the user which repo the issue will be created in if it's available:

This PR fixes #2099.

[mikeseese]

@microsoft-github-policy-service agree

[alexr00]

Thanks for the PR! I have some comments.

[mikeseese]

@alexr00 It got a little more complex, but now origin will contain information to reproduce the correct folder manager and remote by adding a new repo URI scheme.

[rzhao271]

Merge conflict
Moving the milestone

[mikeseese]

@rzhao271 @alexr00 Merge conflicts have been resolved. This PR is still waiting for a rereview. Thanks!

[alexr00]

Thanks for your patience on this! I'll look at it next week when we start our annual clean up iteration.

[alexr00]

@mikeseese, I had some significant changes I wanted with regard to the URI related opterations and schemes. Rather than make you go through more back and forth to make changes that are really my own debt, I've pushed the changes to your branch. I plan to merge the PR after we release this week. Thank you for the PR!

[mikeseese]

Sounds good, thanks!