Made `Path::name` only have item name rather than full name
Closes#134853
This PR makes `Path::name` to only have item name rather than full name, i.e. with the following code
```rust
pub mod foo {
pub struct Bar;
}
pub fn get_bar() -> foo::Bar {
foo::Bar
}
```
and running `./rustdoc ./demo.rs -wjson -Zunstable-options` gives:
```json
{
"41": {
"id": 41,
"name": "get_bar",
"inner": {
"function": {
"sig": {
"inputs": [],
"output": {
"resolved_path": {
"name": "Bar",
"id": 0,
"args": { "angle_bracketed": { "args": [], "constraints": [] }
}
}
}
}
}
}
}
}
```
_Information which isn't useful here was trimmed_
r? aDotInTheVoid