This fixes a bug where a Python script file would be run on a scene file
that didn't have a script file set.
Added a general case version to SceneBuilderWorker.cpp, to make it easy
to mark all scene files as dirty.
Automated tests for this will come in a separate pull request.
Signed-off-by: stankowi <4838196+AMZN-stankowi@users.noreply.github.com>
AMZN-stankowi
69b5c04b7f