Update clipping rects in ui_layout_system

[ickshonpe]

Objective

Perform UI clipping updates during the walk to update the rest of the layout properties.

Solution

• Removed update_clipping_system and renamed the update module to update_target_cameras.
• Migrated the queries and clipping update logic from update_clipping_systems to the update_uinode_geometry_recursive function in the layout module.
• Nodes with Display::None set and their descendants don't need a full update, so added a second function to layout called hide_uinodes_recursive that just walks down the tree and sets the node sizes to zero.

Results

cargo run --example many_buttons --release --features "bevy/trace_tracy"

Yellow is this PR, red is main.

The layout for many_buttons is very shallow and I'd expect most Bevy UI apps will see larger improvements in layout performance (but at the same time they'll have probably use less nodes so the absolute gains will be smaller).

cargo run --example many_buttons --release --features "bevy/trace_tracy" -- --display-none

[ickshonpe]

I'll do some benchmarks a bit later this evening. Typically it seems to only be a ~10% improvement overall but something like a modal UI with a very deep tree that uses Display::None to hide the inactive elements you would see very large improvements.