Rollup merge of #82287 - r00ster91:field_name_and, r=petrochenkov

Make "missing field" error message more natural

```rust
struct A {
    x: i32,
    y: i32,
    z: i32,
}

fn main() {
    A { };
}
```
```
error[E0063]: missing fields `x`, `y`, `z` in initializer of `A`
 --> src/main.rs:8:5
  |
8 |     A { };
  |     ^ missing `x`, `y`, `z`
```
This error is now:
```
error[E0063]: missing fields `x`, `y` and `z` in initializer of `A`
 --> src/main.rs:8:5
  |
8 |     A { };
  |     ^ missing `x`, `y` and `z`
```
I thought it looked nicer and more natural this way. Also, if there is >3 fields missing, there is an "and" as well ("missing \`x\`, \`y\`, \`z\` *and* 1 other field"), but for <=3 there is not. As such it improves consistency too.

As for the implementation, originally I ended up with a chunky `push_str` algorithm but then I figured I could just do the formatting manually since it's just 3 field names at maximum. It is comparatively readable.

As a sidenote, one thing I was wondering about is, isn't there more cases where you have a list of things like field names? Maybe this whole thing can at some point later be made into a more general function to be used in multiple areas.

src/test/ui/issues/issue-79593.rs

@@ -23,7 +23,7 @@ fn wrong() {
     foo::Enum::Variant { x: () };
     //~^ ERROR missing field `y` in initializer of `Enum`
     foo::Enum::Variant { };
-    //~^ ERROR missing fields `x`, `y` in initializer of `Enum`
+    //~^ ERROR missing fields `x` and `y` in initializer of `Enum`
 }
 
 fn main() {}

src/test/ui/issues/issue-79593.stderr

@@ -22,11 +22,11 @@ error[E0063]: missing field `y` in initializer of `Enum`
 LL |     foo::Enum::Variant { x: () };
    |     ^^^^^^^^^^^^^^^^^^ missing `y`
 
-error[E0063]: missing fields `x`, `y` in initializer of `Enum`
+error[E0063]: missing fields `x` and `y` in initializer of `Enum`
   --> $DIR/issue-79593.rs:25:5
    |
 LL |     foo::Enum::Variant { };
-   |     ^^^^^^^^^^^^^^^^^^ missing `x`, `y`
+   |     ^^^^^^^^^^^^^^^^^^ missing `x` and `y`
 
 error: aborting due to 5 previous errors