testsuite: Consolidate spectest into a single binary

[rdmark]

Eliminate spectest_t2, failed_spectest, sleeptest and rotest executables. These test suites have all been folded into afp_spectest. A new option -F has been introduced which selects the suite to run.

All tests that were previously in the failed testsuite have been moved back into spectest, but flagged as "Mac" tests. This doesn't mean I've tested them against a Mac OS AFP server, however the failed suite was described as containing tests that work with Mac AFP but fail with Netatalk.

Set up GitHub actions for logintest and rotest, while adding AFP 2.1 coverage as well.

Touch up the encodingtest to get it running (but not passing.)

Flag all testsuite executables for installation.

[sonarcloud[bot]]

Quality Gate passed

Issues
6 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud