## Objective
Use the "standard" text size / placement for the new text in these
examples.
Continuation of an effort started here:
https://github.com/bevyengine/bevy/pull/8478
This is definitely not comprehensive. I did the ones that were easy to
find and relatively straightforward updates. I meant to just do
`3d_shapes` and `2d_shapes`, but one thing lead to another.
## Solution
Use `font_size: 20.0`, the default (built-in) font, `Color::WHITE`
(default), and `Val::Px(12.)` from the edges of the screen.
There are a few little drive-by cleanups of defaults not being used,
etc.
## Testing
Ran the changed examples, verified that they still look reasonable.
06f733b16f