Replace checkboxes with Compound checkboxes, and appropriately label each checkbox. (#29363)

* Fix labelling of avatar menu

* Make the integration manager toggle more clear.

* fix label

* lint

* Update snapshots.

* Refactor many cases of checkbox to use the new compound component.

* Remove non-checkbox related changes

* Reset some things

* Remove usages of mx_checkbox* styling.

* Use label locators for apperance tests.

* small linter tweaks

* lint

* update screenshot

* Test updates

* lint

* Realign checkboxes for device selection.

* Fixup QuickSettings styling

* remove comment

* lint

* flex comment

* remove unused label

* remove redundant classes

* add test for spaces

* lint

* Copyright

* fixup spaces test

* spaces lint

* Replace pin with compound pin.

* Realign icons

* Remove hack for colouring icons

* Adjust existing rooms component to correctly label room.

* Add test for adding an existing room to an existing space.

* Set deterministic sort order for rooms

* lint

res/css/views/elements/_LabelledCheckbox.pcss

@@ -1,5 +1,5 @@
 /*
-Copyright 2024 New Vector Ltd.
+Copyright 2024,2025 New Vector Ltd.
 Copyright 2022 The Matrix.org Foundation C.I.C.
 
 SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only OR LicenseRef-Element-Commercial
@@ -7,26 +7,5 @@ Please see LICENSE files in the repository root for full details.
 */
 
 .mx_LabelledCheckbox {
-    display: flex;
-    gap: 8px;
-    flex-direction: row;
-
-    .mx_Checkbox {
-        margin-top: 3px; /* visually align with label text */
-    }
-
-    .mx_LabelledCheckbox_labels {
-        flex: 1;
-
-        .mx_LabelledCheckbox_label {
-            vertical-align: middle;
-        }
-
-        .mx_LabelledCheckbox_byline {
-            display: block;
-            padding-top: $spacing-4;
-            color: $muted-fg-color;
-            font-size: $font-11px;
-        }
-    }
+    margin-top: var(--cpd-space-2x);
 }