Fix remote clients unable to query custom, lsp_ext, commands (#27775)

Closes https://github.com/zed-industries/zed/issues/20583
Closes https://github.com/zed-industries/zed/issues/27133

A preparation for rust-analyzer's LSP tasks fetching, ensures all remote
clients are able to query custom, lsp_ext, commands.

Release Notes:

- Fixed remote clients unable to query custom, lsp_ext, commands

crates/proto/src/proto.rs

@@ -302,6 +302,8 @@ messages!(
     (GetImplementationResponse, Background),
     (GetLlmToken, Background),
     (GetLlmTokenResponse, Background),
+    (LanguageServerIdForName, Background),
+    (LanguageServerIdForNameResponse, Background),
     (OpenUnstagedDiff, Foreground),
     (OpenUnstagedDiffResponse, Foreground),
     (OpenUncommittedDiff, Foreground),
@@ -580,6 +582,7 @@ request_messages!(
     (UpdateWorktree, Ack),
     (UpdateRepository, Ack),
     (RemoveRepository, Ack),
+    (LanguageServerIdForName, LanguageServerIdForNameResponse),
     (LspExtExpandMacro, LspExtExpandMacroResponse),
     (LspExtOpenDocs, LspExtOpenDocsResponse),
     (SetRoomParticipantRole, Ack),
@@ -714,6 +717,7 @@ entity_messages!(
     OpenServerSettings,
     GetPermalinkToLine,
     LanguageServerPromptRequest,
+    LanguageServerIdForName,
     GitGetBranches,
     UpdateGitBranch,
     ListToolchains,