Improving "Export Pull Request to Github" functionality

[ndiego]

I have been experimenting with "Export Pull Request to Github" feature, and while it works quite well, there are a few options that would improve this workflow.

• Add the option to create a "Draft" PR instead of a newly published PR
• Add the option to set the PR title. Currently, you have to go into the PR and update the title, which is a bit tedious.

[jarekmorawski]

Could something like this work? cc @adamziel

export_gh.mov