Add Snapping Options to the Snap Dropdown Menu (#1321)

* [wip]feat: add snapping options

* [wip]fix: use svelte component for optionsWidget

* fix: use apt PopoverButton types

* refactor: minor formatting improvements

* Fix popover layout

* [wip]feat: attempt implementing CheckboxInputData struct

* fix: use correct Checkbox struct 's default method

* fix: revert adding CheckboxInputData struct

- This reverts commit 2a481887fc.

* feat: use checkboxes for snapping options

* feat: add label to dropdown checkbox elements

* fix: separate Snap dropdown menu elements
- move each element into separate row

* [wip]feat: modularize snapping states
- maintain individual snapping states for document

* fix: snapping checkboxes' behavior
- checkboxes now update internal snapping state

* refactor: update snap states individually
- this prevents out-of-sync states
- enables reusing existing snap state object

* feat: snap to boxes and nodes conditionally

* [wip]feat: attempt to invert checkbox on update
- attempt implementing mutable WidgetCallback struct
- attempt using above struct to invert checkbox state on update

* Fix widget diffing

* refactor: remove unused code

* feat: align checkboxes consistently with labels

* feat: use separators to stylize snapping menu
- removes need for custom CSS and label property
- ensures consistency across the application

* refactor: remove unneeded css

---------

Co-authored-by: hypercube <0hypercube@gmail.com>, TrueDoctor <dennis@kobert.dev>

frontend/src/components/widgets/WidgetLayout.svelte

@@ -1,5 +1,5 @@
 <script lang="ts">
-	import { isWidgetColumn, isWidgetRow, isWidgetSection, type WidgetLayout } from "@graphite/wasm-communication/messages";
+	import { isWidgetColumn, isWidgetRow, isWidgetSection, LayoutGroup, type WidgetLayout } from "@graphite/wasm-communication/messages";
 
 	import WidgetSection from "@graphite/components/widgets/groups/WidgetSection.svelte";
 	import WidgetRow from "@graphite/components/widgets/WidgetRow.svelte";