Adds a way to toggle font size without settings adjustments (#24857)

Closes https://github.com/zed-industries/zed/issues/23505

Now `zed::IncreaseBufferFontSize` (and all the same UI- and
Buffer-related settings) action is parameterized with `{ "persist": true
}` (default).
Using `"persist": false` brings back resizing behavior prior to
https://github.com/zed-industries/zed/pull/23265


Release Notes:

- Added a way to toggle font size without settings adjustments

crates/editor/src/editor.rs

@@ -162,7 +162,10 @@ use std::{
 pub use sum_tree::Bias;
 use sum_tree::TreeMap;
 use text::{BufferId, OffsetUtf16, Rope};
-use theme::{ActiveTheme, PlayerColor, StatusColors, SyntaxTheme, ThemeColors, ThemeSettings};
+use theme::{
+    observe_buffer_font_size_adjustment, ActiveTheme, PlayerColor, StatusColors, SyntaxTheme,
+    ThemeColors, ThemeSettings,
+};
 use ui::{
     h_flex, prelude::*, ButtonSize, ButtonStyle, Disclosure, IconButton, IconName, IconSize, Key,
     Tooltip,
@@ -1454,6 +1457,7 @@ impl Editor {
                 cx.observe_in(&display_map, window, Self::on_display_map_changed),
                 cx.observe(&blink_manager, |_, _, cx| cx.notify()),
                 cx.observe_global_in::<SettingsStore>(window, Self::settings_changed),
+                observe_buffer_font_size_adjustment(cx, |_, cx| cx.notify()),
                 cx.observe_window_activation(window, |editor, window, cx| {
                     let active = window.is_window_active();
                     editor.blink_manager.update(cx, |blink_manager, cx| {
@@ -16143,7 +16147,7 @@ impl Render for Editor {
                 font_family: settings.buffer_font.family.clone(),
                 font_features: settings.buffer_font.features.clone(),
                 font_fallbacks: settings.buffer_font.fallbacks.clone(),
-                font_size: settings.buffer_font_size().into(),
+                font_size: settings.buffer_font_size(cx).into(),
                 font_weight: settings.buffer_font.weight,
                 line_height: relative(settings.buffer_line_height.value()),
                 ..Default::default()