Implementation plan for Adding mutations and CNA gene charts to study view

[jjgao]

Start by creating the CNA pie chart. Later we can figure out what we want to do for the mutations
chart.

1. Add a CNA filter to the StudyViewFilter
2. Add logic to the StudyViewFilterApplier. Mock services, do not implment them.
3. Create a mock API by fully implementing the controller classes, and calling the mock services
4. Create the pie chart in the frontend
5. Implement the service, repo, and mapping layer

[inodb]

See #6759