Add support for git branches on remote projects (#19755)

Release Notes:

- Fixed a bug where the branch switcher could not be used remotely.

crates/proto/proto/zed.proto

@@ -281,7 +281,12 @@ message Envelope {
         FlushBufferedMessages flush_buffered_messages = 267;
 
         LanguageServerPromptRequest language_server_prompt_request = 268;
-        LanguageServerPromptResponse language_server_prompt_response = 269; // current max
+        LanguageServerPromptResponse language_server_prompt_response = 269;
+
+        GitBranches git_branches = 270;
+        GitBranchesResponse git_branches_response = 271;
+
+        UpdateGitBranch update_git_branch = 272; // current max
     }
 
 
@@ -2432,3 +2437,24 @@ message LanguageServerPromptRequest {
 message LanguageServerPromptResponse {
     optional uint64 action_response = 1;
 }
+
+message Branch {
+    bool is_head = 1;
+    string name = 2;
+    optional uint64 unix_timestamp = 3;
+}
+
+message GitBranches {
+    uint64 project_id = 1;
+    ProjectPath repository = 2;
+}
+
+message GitBranchesResponse {
+    repeated Branch branches = 1;
+}
+
+message UpdateGitBranch {
+    uint64 project_id = 1;
+    string branch_name = 2;
+    ProjectPath repository = 3;
+}

crates/proto/src/proto.rs

@@ -357,6 +357,9 @@ messages!(
     (FlushBufferedMessages, Foreground),
     (LanguageServerPromptRequest, Foreground),
     (LanguageServerPromptResponse, Foreground),
+    (GitBranches, Background),
+    (GitBranchesResponse, Background),
+    (UpdateGitBranch, Background)
 );
 
 request_messages!(
@@ -473,6 +476,8 @@ request_messages!(
     (GetPermalinkToLine, GetPermalinkToLineResponse),
     (FlushBufferedMessages, Ack),
     (LanguageServerPromptRequest, LanguageServerPromptResponse),
+    (GitBranches, GitBranchesResponse),
+    (UpdateGitBranch, Ack)
 );
 
 entity_messages!(
@@ -550,7 +555,9 @@ entity_messages!(
     HideToast,
     OpenServerSettings,
     GetPermalinkToLine,
-    LanguageServerPromptRequest
+    LanguageServerPromptRequest,
+    GitBranches,
+    UpdateGitBranch
 );
 
 entity_messages!(