Fix CI test configuration, so that pytest can import the package code

Set %__python3 value according to %python3_pkgversion

Fix multiline arguments processing for %py_check_import
Fix %py_shebang_flags handling within %py_check_import
Process .pth files in buildroot's sitedirs in %py_check_import
Move import_all_modules.py from python-srpm-macros to python-rpm-macros

Introduce -f (read from file) option to %py{3}_check_import
Introduce -t (filter top-level modules) option to %py{3}_check_import
Introduce -e (exclude module globs) option to %py{3}_check_import

Set $RPM_BUILD_ROOT in %{python3_...} macros

Define a new macros %python_wheel_dir and %python_wheel_pkg_prefix
Related: rhbz#1982668

Rebuilt for IMA sigs, glibc 2.34, aarch64 flags

Introduce %py3_check_import

%pytest: Set $PYTEST_ADDOPTS when %{__pytest_addopts} is defined

Fix %python_provide when fed python3.10-foo to obsolete python-foo instead of python--foo

Escape % symbols in macro files comments
Fixes: rhbz#1953910

Use sysconfig.get_path() to get %python3_sitelib and %python3_sitearch
Fixes: rhbz#1947468

Allow commas as argument separator for extras names in %python_extras_subpkg
Fixes: rhbz#1936486

Rebuilt for RHEL 9 BETA on Apr 15th 2021. Related: rhbz#1947937

Fix %python_extras_subpkg with underscores in extras names

Remove python2-rpm-macros
https://fedoraproject.org/wiki/Changes/Disable_Python_2_Dist_RPM_Generators_and_Freeze_Python_2_Macros