* Tests: fix random selection of deleted record causing test failure
* Tests: fix test folders being left after test
* Tests: ensure that required records are available
* Tests: make each package execute against it's own testdata folder to ensure no interpackage test failures
* Tests: add unit tests of CleanupTestFolder
* Tests: Allow defer in TestMain
* Tests: rename testMain to runTestMain
This is necessary to provide external services with temporary access to
specific media files without giving them permanent access, a regular
download, or an access token.
Signed-off-by: Michael Mayer <michael@photoprism.app>