Rollup merge of #103575 - Xiretza:suggestions-style-attr, r=davidtwco

Change #[suggestion_*] attributes to use style="..."

As discussed [on Zulip](https://rust-lang.zulipchat.com/#narrow/stream/336883-i18n/topic/.23100717.20tool_only_span_suggestion), this changes `#[(multipart_)suggestion_{short,verbose,hidden}(...)]` attributes to plain `#[(multipart_)suggestion(...)]` attributes with a `style = "{short,verbose,hidden}"` parameter.

It also adds a new style, `tool-only`, that corresponds to `tool_only_span_suggestion`/`tool_only_multipart_suggestion` and causes the suggestion to not be shown in human-readable output at all.

Best reviewed commit-by-commit, there's a bit of noise in there.

cc #100717 `@compiler-errors`
r? `@davidtwco`

compiler/rustc_infer/src/errors/mod.rs

@@ -109,8 +109,9 @@ pub struct InferenceBadError<'a> {
 
 #[derive(Subdiagnostic)]
 pub enum SourceKindSubdiag<'a> {
-    #[suggestion_verbose(
+    #[suggestion(
         infer_source_kind_subdiag_let,
+        style = "verbose",
         code = ": {type_name}",
         applicability = "has-placeholders"
     )]
@@ -135,8 +136,9 @@ pub enum SourceKindSubdiag<'a> {
         parent_prefix: String,
         parent_name: String,
     },
-    #[suggestion_verbose(
+    #[suggestion(
         infer_source_kind_subdiag_generic_suggestion,
+        style = "verbose",
         code = "::<{args}>",
         applicability = "has-placeholders"
     )]
@@ -150,8 +152,9 @@ pub enum SourceKindSubdiag<'a> {
 
 #[derive(Subdiagnostic)]
 pub enum SourceKindMultiSuggestion<'a> {
-    #[multipart_suggestion_verbose(
+    #[multipart_suggestion(
         infer_source_kind_fully_qualified,
+        style = "verbose",
         applicability = "has-placeholders"
     )]
     FullyQualified {
@@ -163,8 +166,9 @@ pub enum SourceKindMultiSuggestion<'a> {
         adjustment: &'a str,
         successor_pos: &'a str,
     },
-    #[multipart_suggestion_verbose(
+    #[multipart_suggestion(
         infer_source_kind_closure_return,
+        style = "verbose",
         applicability = "has-placeholders"
     )]
     ClosureReturn {
@@ -478,8 +482,9 @@ pub enum ImplicitStaticLifetimeSubdiag {
         #[primary_span]
         span: Span,
     },
-    #[suggestion_verbose(
+    #[suggestion(
         infer_implicit_static_lifetime_suggestion,
+        style = "verbose",
         code = " + '_",
         applicability = "maybe-incorrect"
     )]