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

assets/keymaps/linux/jetbrains.json

@@ -9,8 +9,8 @@
   {
     "context": "Editor",
     "bindings": {
-      "ctrl->": "zed::IncreaseBufferFontSize",
-      "ctrl-<": "zed::DecreaseBufferFontSize",
+      "ctrl->": ["zed::IncreaseBufferFontSize", { "persist": true }],
+      "ctrl-<": ["zed::DecreaseBufferFontSize", { "persist": true }],
       "ctrl-shift-j": "editor::JoinLines",
       "ctrl-d": "editor::DuplicateSelection",
       "ctrl-y": "editor::DeleteLine",