Add ide-assist: generate_inverse_ops_impl

[A4-Tacks]

Generate inverse ops implement.

Example

struct Foo(i32);
impl core::ops::Add<i32> $0for Foo {
    type Output = i32;

    fn add(self, rhs: i32) -> Self::Output {
        self.0 + rhs
    }
}

->

struct Foo(i32);
impl core::ops::Add<Foo> for i32 {
    type Output = i32;

    fn add(self, rhs: Foo) -> Self::Output {
        rhs.0 + self
    }
}

impl core::ops::Add<i32> for Foo {
    type Output = i32;

    fn add(self, rhs: i32) -> Self::Output {
        self.0 + rhs
    }
}