Rename consuming chaining methods on DiagnosticBuilder.

In #119606 I added them and used a `_mv` suffix, but that wasn't great.

A `with_` prefix has three different existing uses.
- Constructors, e.g. `Vec::with_capacity`.
- Wrappers that provide an environment to execute some code, e.g.
  `with_session_globals`.
- Consuming chaining methods, e.g. `Span::with_{lo,hi,ctxt}`.

The third case is exactly what we want, so this commit changes
`DiagnosticBuilder::foo_mv` to `DiagnosticBuilder::with_foo`.

Thanks to @compiler-errors for the suggestion.

compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs

@@ -969,7 +969,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                                     self.tcx().def_span(impl_def_id),
                                     "multiple drop impls found",
                                 )
-                                .span_note_mv(
+                                .with_span_note(
                                     self.tcx().def_span(old_impl_def_id),
                                     "other impl here",
                                 )