test_schedule_tmt: Fix collecting SUT install commands
Commit b7bc2942 picked up an obsolete way of reading the install commands via a shared function. But commit e0f47392 changed that to writing to a file. Adjust writing tmt-reproducer.sh to read the file instead, like in the testing-farm branch.
Port the COPR and koji TMT scheduler tests from the testing-farm branch to exercise that code path.
Plus a few other fixes. I'd like to get this all working before I change the tmt-reproducer.sh generation for issue #12 (closed).
Edited by Martin Pitt