PR #128051 made some improvements to code by cleaning up properties and
simplifying logic.
However, the default tool in most spaces is box select. By switching to
box select default, there should be more front-facing consistency across
spaces while still retaining near-identical behavior.
This patch would fix the small bug listed in #128671 while keeping the
simplified code benefits from #128051.
Also:
- Move selection keymap items up in the Sequencer (Global) keymap so it
is more visible (similar to Node Editor ordering).
- Split `side_of_frame` property for ctrl press keymap item into a
separate keymap item on ctrl click for both LCS and RCS to avoid
clashing with ctrl+drag for box selects in RCS.
Pull Request: https://projects.blender.org/blender/blender/pulls/129028