This extension has a code action that can be triggered when creating a comment that starts with key words like "TODO":

Once it is created, you can hover over the issue number and see the following:

It would be helpful if there was a command to open the issue (similar to the command pr.openPullRequestOnGitHub but for the current issue that is hovered on.

Complexity wise, this seems really simple to implement (maybe 10 - 20 lines of code).