gpui: Add text alignment (#24090)

Adds a text property for controlling left, center, or right text
alignment.

#8792 should stay open since this doesn't add support for `justify`
(which would require a much bigger change since this can just alter the
origin of each line, but justify requires changing spacing, whereas
justify requires changes to each platform's shaping code).

Release Notes:

- N/A

crates/gpui/src/elements/div.rs

@@ -1661,6 +1661,8 @@ impl Interactivity {
         window: &mut Window,
         cx: &mut App,
     ) {
+        use crate::TextAlign;
+
         if global_id.is_some()
             && (style.debug || style.debug_below || cx.has_global::<crate::DebugBelow>())
             && hitbox.is_hovered(window)
@@ -1682,7 +1684,8 @@ impl Interactivity {
                     .ok()
                     .and_then(|mut text| text.pop())
                 {
-                    text.paint(hitbox.origin, FONT_SIZE, window, cx).ok();
+                    text.paint(hitbox.origin, FONT_SIZE, TextAlign::Left, window, cx)
+                        .ok();
 
                     let text_bounds = crate::Bounds {
                         origin: hitbox.origin,