[BUG] Nested `Printer::with_color` leading to unexpected behavior

**Describe the bug**
`Printer::with_color` and similar functions are implemented by mutating the printer itself without mutably borrowing it, leading to unexpected (or wrong) behavior when being used nestedly.

**To Reproduce**
```rust
use cursive::{theme::BaseColor, views::Canvas};

fn main() {
let ref mut s = cursive::default();
s.add_layer(
Canvas::new(())
.with_draw(|_, printer| {
printer.with_color(BaseColor::Red.into(), |p_red| {
printer.with_color(BaseColor::Black.into(), |p_black| {
p_red.print((0, 0), "should be red");
p_black.print((0, 1), "should be black");
})
})
})
.with_required_size(|_, _| (20, 10).into()),
);
s.run();
}
```
Run, and see both lines being black.

**Expected behavior**
The first line of text should be red.
Or this code should fail to compile.

**Screenshots**
Actual:
Expected:

**Environment**
* Operating system used: Windows Terminal & ConHost on Windows 10
* Backend used: crossterm
* Current locale: zh_CN.UTF-8
* Cursive version: 0.18.0 from crates.io

**Additional context**
Well I *do* know that it should not be used like this. But imo such a usage should, and probably could be prevented by borrowing the printer mutably.

BTW I came across this when trying to get two printers with same offset and different color in the same scope. Is there a better way for this?