chore: reorganize mocks

Most of the mocks are organized into subdirectories by Connect version. The default mock directory is named 2024.08.0 but it actually does not contain a version number in its server settings. The other mock directories do respond like the named Connect version.

Some options:

• At the very least, the default mock directory should be renamed something like unversioned (with a note in a README to describe what that means). This might be fine for tests that use code that doesn't explicitly check the Connect version.
• Another option would be to remove the default mock path and always be explicit (described by @nealrichardson here). Even code that doesn't explicitly check a version of Connect is written against some version, so it might just be good practice to put any mock in a directory for the version of Connect it was captured from.

Start by comparing the mock subdirectories, especially the default 2024.08.0 directory, with their server settings and versioned peers. Read the discussion linked in the issue before choosing between renaming the default directory or removing the default mock path; done means the layout and README or test references consistently reflect the decision.