Unify mock_data.js files into one
We've 3 mock_data.js
files:
spec/frontend/account/mock_data.js
spec/frontend/purchase/mock_data.js
spec/frontend/subscription/mock_data.js
We need to unify all the mock data into a single file and update all references to the mock data in the tests.
Related to https://gitlab.com/gitlab-org/fulfillment-meta/-/issues/111