Add Caps Lock support (#30470)

Closes #21700

Release Notes:

- Added caps lock support and show a warning if the user is entering an
SSH password with Caps Lock enabled

---------

Co-authored-by: Mikayla Maki <mikayla@zed.dev>
Co-authored-by: Mikayla Maki <mikayla.c.maki@gmail.com>
Co-authored-by: 张小白 <364772080@qq.com>

crates/gpui/src/platform/linux/platform.rs

@@ -873,6 +873,14 @@ impl crate::Modifiers {
     }
 }
 
+#[cfg(any(feature = "wayland", feature = "x11"))]
+impl crate::Capslock {
+    pub(super) fn from_xkb(keymap_state: &State) -> Self {
+        let on = keymap_state.mod_name_is_active(xkb::MOD_NAME_CAPS, xkb::STATE_MODS_EFFECTIVE);
+        Self { on }
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;