We should never select something that is hidden in the viewport.
Generally, there can be multiple reasons why keyframe handles are not
shown in the Graph Editor:
- the `View` > `Show Handles` option is disabled
- the `Only Show Selected Keyframes Handles` is enabled
- a keyframe `Interpolation` method is anything but `Bezier`
This PR corrects the first.
Details:
- In `box_select_graphkeys()`, the `incl_handles` parameter is only
be passed to `initialize_box_select_key_editing_data()`
- add a separate `KEYFRAME_ITER_HANDLES_INVISIBLE` flag (representing
SIPO_NOHANDLES)
- "include_handles" purely represents operator setting / user intend now
- "final" decision about handles/their visibility is done in
`keyframe_ok_checks()` etc
For consistency, add "include_handles" option to Lasso/Circle as well
Part of #139314
Pull Request: https://projects.blender.org/blender/blender/pulls/139349
b254a1ac36