Suggest removing "empty" `format!` for types that implement `fmt::Display`

[LynxDev2]

What it does

When format!("{x}") or format!("{}", x) is used and the type of x implements fmt::Display, clippy should suggest using .to_string() directly

I'm not sure if there's already an issue for this, but I couldn't find one

Advantage

No response

Drawbacks

No response

Example

let addr = SocketAddr::from(([127, 0, 0, 1], 80));
let addr_string = format!("{addr}");

Could be written as:

let addr = SocketAddr::from(([127, 0, 0, 1], 80));
let addr_string = addr.to_string();

[samueltardieu]

Clippy should suggest changing the second line to let addr_string = addr.to_string();

Why should it? Is there an advantage in using the form you suggest?

[LynxDev2]

Well imo it looks cleaner since using format! is unnecessary here since it's not being formatted with anything else, just converted

[y21]

Some prior discussion on this: #3753 #3156

[samueltardieu]

I don't think we should force this on people, as for many reasons (consistency, readability, etc.) some people or some projets may prefer to use format!(), and there are no performance gain in converting this.

The main question IMO is: would enough people turn it on if it was a restriction lint for the lint to be useful?