Enable Pending Tasks section on new dash

Add Pending Tasks section to the following tabs:
* Course Info
* Student Email
* Data Download
* Email

LMS-1242
Reorganize Course Info dash section

LMS-1242
Move PIT code into util.coffee
Add testing coverage
LMS-1242

Add "Edit This Course In Studio" link for studio courses
LMS-1291
Make event handlers fire properly

Respond to review comments

LMS-1242