Python and Python developers don't like directory names to include a
minus sign, like "cql-pytest". In this patch we rename test/cql-pytest
to test/cqlpy, and also change a few references in other code (e.g., code
that used test/cql-pytest/run.py) and also references to this test suite
in documentation and comments.
Arguably, the word "test" was always redundant in test/cql-pytest, and
I want to leave the "py" in test/cqlpy to emphasize that it's Python-based
tests, contrasting with test/cql which are CQL-request-only approval
tests.
Fixes#20846
Signed-off-by: Nadav Har'El <nyh@scylladb.com>