Allows NLA strips to horizontally translated over each other. If a strip is dropped when translating, it'll cause the strip to shuffle into place. --- Abstracted large conditional branch in `recalcData_nla` into it's own `nlastrip_fix_overlapping` method for increased readability. No logical changes were made. --- [Archived Phabricator Patch](https://archive.blender.org/developer/D10102) Pull Request: https://projects.blender.org/blender/blender/pulls/105532