Blender Git Loki

Bugfix [35841] WM_OT_context_[toggle/cycle/etc.] operators dont show shortcut
keys in menus (or tooltips) for properties they are used to toggle/cycle through

Some properties can be toggled using hotkeys via WM_OT_context_* operators, but
these hotkeys aren't really shown anywhere obvious like other hotkeys (i.e.
they're not shown in tooltips or menus). Although it is possible to look these
up in the userprefs/keymaps editor, it is quite tricky doing so, and most users
would just assume that since no shortcut is displayed, there simply isn't one at
all.

This commit introduces a slightly hacky fix which basically amounts to checking
if a property can be set by any of the few operators which are used for this
purpose. In order to keep this from being too sluggish, I've currently limited
this to only working on Editor (e.g. "Show Seconds" in Anim Editors) and
ToolSettings (e.g. "Use Proportional Edit") properties.

There are still some corner cases that would be nice to solve too (i.e. the
Pivot Type enum menu/dropdown should really be able to show the hotkeys which
have been assigned for each of those items, since they're by-and-large quite
hidden and obscure), though being able to show some of these is perhaps better
than not showing any!