Fix build error with tests for removed functions

These GHash functions were removed in 12817083ec61,
so the tests should be removed too.

Cleanup: Use bool instead of int

UI: Add shortcuts for shader effect panels

Only the delete shortcut applies here, although the move up and down
operators can optionally be assigned in the keymap.

See rB1fa40c9f8a81 for more details and rB5d2005cbb54b for the
grease pencil modifier panel implementation, which is the same.

Fix T77730: ShaderFx Missing Update Notifier

This adds a notification type for shaderfx so the properties editor can
be properly notified to redraw.

Another possible solution would be to also redraw the shaderfx tab
with a ND_MODIFIER update, but this solution allows us to avoid
some unecessary redraws too. There were no existing cases of
ND_OBJECT | NC_MODIFIER updates, so those cases were
removed from buttons_area_listener.

Differential Revision: https://developer.blender.org/D8159

Cleanup: Deduplicate code for finding context object

Instead of manually checking the pinned object, use the existing
ED_object_active_context function. This requires adding const
to the context in that function.

UI: Fix bevel modifier not showing vertex group

Cleanup: Remove redundant logic

Fix memory leak when dragging shaderfx

UI: Use sliders and [0, 1] ranges in ocean modifier

The ocean modifier has two properties that use a [0, 10] hard min and
hard max. The values act as factors though, so it makes more sense to
use sliders and a 0 to 1 range.

This commit also bumps the file subversion to avoid repeatedly applying
the change to the properties' range.

Differential Revision: https://developer.blender.org/D8186

Cleanup: Unused variables in non-debug build