remote dev: Allow canceling language server work in editor (#19946)

Release Notes:

- Added ability to cancel language server work in remote development.

Demo:



https://github.com/user-attachments/assets/c9ca91a5-617f-4886-a458-87c563c5a247

crates/proto/proto/zed.proto

@@ -292,7 +292,9 @@ message Envelope {
         GetPathMetadataResponse get_path_metadata_response = 279;
 
         GetPanicFiles get_panic_files = 280;
-        GetPanicFilesResponse get_panic_files_response = 281; // current max
+        GetPanicFilesResponse get_panic_files_response = 281;
+
+        CancelLanguageServerWork cancel_language_server_work = 282; // current max
     }
 
     reserved 87 to 88;
@@ -1257,12 +1259,14 @@ message LspWorkStart {
     optional string title = 4;
     optional string message = 2;
     optional uint32 percentage = 3;
+    optional bool is_cancellable = 5;
 }
 
 message LspWorkProgress {
     string token = 1;
     optional string message = 2;
     optional uint32 percentage = 3;
+    optional bool is_cancellable = 4;
 }
 
 message LspWorkEnd {
@@ -2500,3 +2504,21 @@ message GetPanicFiles {
 message GetPanicFilesResponse {
     repeated string file_contents = 2;
 }
+
+message CancelLanguageServerWork {
+    uint64 project_id = 1;
+
+    oneof work {
+        Buffers buffers = 2;
+        LanguageServerWork language_server_work = 3;
+    }
+
+    message Buffers {
+        repeated uint64 buffer_ids = 2;
+    }
+
+    message LanguageServerWork {
+        uint64 language_server_id = 1;
+        optional string token = 2;
+    }
+}

crates/proto/src/proto.rs

@@ -366,6 +366,7 @@ messages!(
     (GetPathMetadataResponse, Background),
     (GetPanicFiles, Background),
     (GetPanicFilesResponse, Background),
+    (CancelLanguageServerWork, Foreground),
 );
 
 request_messages!(
@@ -486,7 +487,8 @@ request_messages!(
     (ActivateToolchain, Ack),
     (ActiveToolchain, ActiveToolchainResponse),
     (GetPathMetadata, GetPathMetadataResponse),
-    (GetPanicFiles, GetPanicFilesResponse)
+    (GetPanicFiles, GetPanicFilesResponse),
+    (CancelLanguageServerWork, Ack),
 );
 
 entity_messages!(
@@ -570,6 +572,7 @@ entity_messages!(
     ActivateToolchain,
     ActiveToolchain,
     GetPathMetadata,
+    CancelLanguageServerWork,
 );
 
 entity_messages!(