Don't store extra copy of all `TestCaseInfo*` in `TestRegistry`

We used to store a full vector of "views" of the registered test infos,
so that it can be retrieved externally. However, the only user of that
interface left was `Session`, specifically `Session::applyFilenameAsTags`.

By moving the adding of the filename tags into the `ITestCaseRegistry`
interface, we avoid storing the vector and make the initial test registration
faster.

The new code is ugly and shows a design/layering issue, but no worse than
the previous approach did.

0 files changed, 0 insertions, 0 deletions