Sort code action completions by importance

This is inspired by a recent change in [Helix] that fixes sorting of
code actions.
We have the same problem; we use ":prompt -shell-script-candidates"
to show code actions.
For example, on this Rust file:

	fn main() {
	    let f: FnOnce(HashMap<i32, i32>);
	}

with the cursor on "HashMap", a ":lsp-code-actions" will use ":prompt"
to offer two code actions from rust-analyzer:

	Extract type as type alias"
	Import `std::collections::HashMap`

The first one is a refactoring and the second one is a quickfix.

A proposed Kakoune patch preserves completion input order (if the
query is empty). Use this to fix the order of above code actions.

[Helix]: helix-editor/helix#4134

src/language_features/code_action.rs

@@ -144,7 +144,7 @@ fn editor_code_actions(
         return;
     }
 
-    let actions: Vec<_> = results
+    let mut actions: Vec<_> = results
         .into_iter()
         .flat_map(|(server_name, cmd)| {
             let cmd: Vec<_> = cmd
@@ -222,6 +222,25 @@ fn editor_code_actions(
         return;
     }
 
+    actions.sort_by_key(|(_server, ca)| {
+        // TODO Group by server?
+        let empty = CodeActionKind::EMPTY;
+        let kind = match ca {
+            CodeActionOrCommand::Command(_) => &empty,
+            CodeActionOrCommand::CodeAction(action) => action.kind.as_ref().unwrap_or(&empty),
+        };
+        // TODO These loosely follow what VSCode does, we should be more accurate.
+        match kind.as_str() {
+            "quickfix" => 0,
+            "refactor" => 1,
+            "refactor.extract" => 2,
+            "refactor.inline" => 3,
+            "refactor.rewrite" => 4,
+            "source" => 5,
+            "source.organizeImports" => 6,
+            _ => 7,
+        }
+    });
     let titles_and_commands = actions
         .iter()
         .map(|(server_name, c)| {