Implement assist to replace named generic with impl

This adds a new assist named "replace named generic with impl" to move
the generic param type from the generic param list into the function
signature.

```rust
fn new<T: ToString>(input: T) -> Self {}
```

becomes

```rust
fn new(input: impl ToString) -> Self {}
```

The first step is to determine if the assist can be applied, there has
to be a match between generic trait param & function paramter types.

* replace function parameter type(s) with impl
* add new `impl_trait_type` function to generate the new trait bounds with `impl` keyword  for use in the
  function signature

0 files changed, 0 insertions, 0 deletions