Add locale-based time formatting in the chat panel (#7945)

This commit addresses the issue of time formats displayed in the chat
panel. Previously, the time was always displayed in a 12-hour format,
regardless of the user's locale. The `format_timestamp` function has
been updated to check the system locale and format the time accordingly.


Release Notes:
- Fixed time formatting in the chat panel to be locale based.

Cargo.toml

@@ -272,6 +272,7 @@ unindent = "0.1.7"
 url = "2.2"
 uuid = { version = "1.1.2", features = ["v4"] }
 wasmtime = "16"
+sys-locale = "0.3.1"
 
 [patch.crates-io]
 tree-sitter = { git = "https://github.com/tree-sitter/tree-sitter", rev = "1d8975319c2d5de1bf710e7e21db25b0eee4bc66" }