Add platform model association with Courses and Programs

[arslanashraf7]

We need to associate courses and programs with platforms e.g. Emeritus or Global Academy. So, courses and programs could be sorted based on the platforms and this data could be used in BI reports and future use cases.

Designs and Mockups

• We need to create a new model that has the platform information and then associate that with Courses and programs through a foreign key and allows us to reuse platforms.

Acceptance Criteria:

• Create a new model Platform, Initially with just one column Platform name
• Allow admins to associate the platforms to courses and programs
• Send this data to BI

[arslanashraf7]

Reopening it. We should close this after merging the PR in data-platform. Or we can create a separate ticket for that.