Incorrect template courses case is currently being handled incorrectly

[PremBharwani]

Scenario: If we have a course in a specific template which is not being offered in the current semester, the app logic doesn't handle this correctly.

For instance if you have "AB123" in the template, and the course_data.js doesn't contain "AB123" then your app would throw an error. This could be resolved by verifying whether each course that is specified in the template is actually being offered, and if not then do not include that in the already selected courses.