Separate tokens

[Xiangs18]

Currently, we use the same token for admin-token and test-token in GHA.

To test things properly in GHA, we need to have separate tokens, one of which should have blobstore admin rights. However, adding blobstore admin to one of the GHA secret tokens is not encouraged by DevOps team as we're running a risk of leaking it.

An alternative approach would be running our own minio, auth, and blobstore in the tests along with mongo, similar to how the workspace does it.