[Feature Request] A `crabtime::escape_string` macro which quotes the string

[meghprkh]

Escaping strings is somewhat painful and needs to happen out of the macro output body. It would be nice if we can make it easier with a crabtime::escape_string macro

Usage:

#[crabtime::expression]
#[macro_export]
pub fn identity_string(icon_name: String) -> String {
    crabtime::output! {
        crabtime::escape_string!(icon_name)
    }
}

let a = identity_string!("A#\"b");
// should generate
let a = r##"A#"b"##;