Refresh rates for egui demo widgets

[White-Rabbit-Scientific]

Sorry. I should not have posted this as an issue (#7335) :-( This is the correct place.

Running egui.rs demo CPU times:

NO widgets displayed = 0.2 ms/frame

ALL widgets displayed except for Font book, Table, Tooltips, and Window options = 1.65 ms/frame

Add Font book --> now 4.3 ms/frame (~2.7 ms/frame !!!)

Add Table --> now 4.7 ms/frame (~0.4 ms/frame !!!)

Add Tooltips --> now 5.4 ms/frame (~0.7 ms/frame !!!)

Add Window options --> now 5.5 ms/frame (~0.1 ms/frame !!!)