allow specifying issue type when getting project issues

[mglaman]

Right now project issues can only be fetched by status. There should be a way to get all support, bugs, tasks, etc.

Docs: https://www.drupal.org/drupalorg/docs/apis/rest-and-other-apis

field_issue_category is the field for the issue type
1 = Bug report
2 = Task
3 = Feature request
4 = Support request
5 = Plan

Use case:

• find all open support issues or find all open/closed support issues to find common problems that could be documented.
• Find all open bug tickets to work on