6b8970d728
When movie strip is added and redo panel is tweaked, operator failed to
re-execute.
Caused by c4eab49b9. This added `sequencer_generic_invoke_xy__internal`
call in operator exec function, but did not specify `SEQPROP_NOPATHS`
argument, which caused `directory` and `filepath` properties to be
overwritten.
This PR adds clarification for `SEQPROP_NOPATHS` use case, because it
isn't immediately obvious what this is doing.
Pull Request: https://projects.blender.org/blender/blender/pulls/140736