feat: add permissions for vibrancy and cursor events (#249)

A small PR that adds permissions for the frontend to use.

Specifically, adds ability to use window effects from the frontend
itself rather than the settings menu (still waiting for
#133), and the ability to make the
bar click-through.

I personally use these features in my Zebar configuration with a custom
Zebar build. I'd love to see these get added so there will be no need to
recompile Zebar to use my configuration.

<!--
Before submitting a PR, follow this checklist:

1. Give the PR a descriptive title.

  Examples of good titles:
    - fix: fix race condition in message loop
    - docs: update readme with new demo gif
    - feat: add new `general.focus_follows_mouse` config option

  Examples of bad titles:
    - fix #7123
    - update docs
    - fix bugs

2. If there is a related issue, reference it in the PR description, e.g.
closes #123.
3. Propose your changes as a draft PR if your work is still in progress.
-->

Author: blaiyz

packages/desktop/capabilities/widget.json

@@ -29,6 +29,8 @@
     "core:window:allow-set-resizable",
     "core:window:allow-set-position",
     "core:window:allow-set-size",
-    "core:window:allow-set-title"
+    "core:window:allow-set-title",
+    "core:window:allow-set-effects",
+    "core:window:allow-set-ignore-cursor-events"
   ]
 }