Git askpass (#25953)

Supersedes #25848

Release Notes:

- git: Supporting push/pull/fetch when remote requires auth

---------

Co-authored-by: Mikayla Maki <mikayla.c.maki@gmail.com>

crates/proto/src/proto.rs

@@ -452,6 +452,8 @@ messages!(
     (GetRemotesResponse, Background),
     (Pull, Background),
     (RemoteMessageResponse, Background),
+    (AskPassRequest, Background),
+    (AskPassResponse, Background),
     (GitCreateBranch, Background),
     (GitChangeBranch, Background),
     (CheckForPushedCommits, Background),
@@ -598,6 +600,7 @@ request_messages!(
     (Fetch, RemoteMessageResponse),
     (GetRemotes, GetRemotesResponse),
     (Pull, RemoteMessageResponse),
+    (AskPassRequest, AskPassResponse),
     (GitCreateBranch, Ack),
     (GitChangeBranch, Ack),
     (CheckForPushedCommits, CheckForPushedCommitsResponse),
@@ -702,6 +705,7 @@ entity_messages!(
     Fetch,
     GetRemotes,
     Pull,
+    AskPassRequest,
     GitChangeBranch,
     GitCreateBranch,
     CheckForPushedCommits,