add api key check to counts v2

[tessalt]

What does this PR do?

Updates the counts v2 endpoint to require either an admin access token or an admin-generated API key

These changes will impact:

• [ ] commenters
• [ ] moderators
• [ ] admins
• [x] developers

What changes to the GraphQL/Database Schema does this PR introduce?

none

Does this PR introduce any new environment variables or feature flags?

If any indexes were added, were they added to INDEXES.md?

How do I test this PR?

enable COUNTS_V2 feature flag

use the createToken mutation to create a token, as an admin user

try making a request to counts v2 without token, see that you get a 401 error

try making a request to coutns v2 with the token, it should succeed

Were any tests migrated to React Testing Library?

How do we deploy this PR?