refactor: import the platform as ascender rather than awx

[blaipr]

Five places name the platform's Python package:

• 'ENGINE': 'awx.main.db.profiled_pg' in the three alternative/ settings files.
• The two imports awx_migrate.sh.j2 makes to rebuild role parentage, awx.main.models.rbac and awx.main.migrations._rbac.

ctrliq/ascender#988 makes every module answer to both names, aliased to one module object rather than imported twice, so this is the same code either way. It is a move off the old name rather than a fix.

Ordering

Needs the Ascender release carrying that alias. Unlike ascender-collection, whose CI tracks the platform's default branch, this repository installs a pinned ASCENDER_VERSION, so these paths only resolve under the old name until a release carries the new one. This cannot go out ahead of it.

The awx_migrate_ascender role keeps its name. It migrates from AWX, so AWX is the right word.

The sibling change for ascender-pro-install is #16.

[cigamit]

I may wait on this one, considering most people just do a git pull of main versus pulling an exact branch.

[blaipr]

Agreed, this one should wait. ascender.main only resolves in a release carrying ctrliq/ascender#988, so anyone pulling main here before that release would get an installer pointing at a module their Ascender does not have.

Nothing is lost by holding it: awx.main keeps working indefinitely, since the alias exists for the entry points in other people's packages rather than for a deprecation window.