Port canvas_integration django app from mitodl/edx-platform

[arslanashraf7]

Subtask of #3

Depends on #7, #6

What needs to be done?
This task will include the effort to port all the Canvas Integration-related code that should/can be moved into a plugin.

The plugin should be created in a way to be supported by edX platform itself. For creating edX extension plugins a good read could be this guide and this utility repo. Following the edX standards, we can make sure that our plugins work with edX without any issues.

Acceptance Criteria:

• Migrate all the canvas_integration Django app code into the open-edx-plugins inside /src directory (Parallelly this part will be removed from edx-platform as part of Create a new branch in mitodl/edx-platform for non plugin parts #6)
• Setup all the configurations in the app to be pip installable within edX-platform
• Setup the BUILD files to generate proper app releases for migrated canvas_integration Django app

[arslanashraf7]

Closed via #8