Replace legacy $spacing-X vars with Compound Design Tokens (#34380)

* Replace legacy `$spacing-X` vars with Compound Design Tokens

* Remove unused font size vars

* Use calc to get negative spacing vars

apps/web/res/css/components/views/polls/_PollOption.pcss

@@ -45,7 +45,7 @@ Please see LICENSE files in the repository root for full details.
     height: 12px;
     width: 12px;
     color: var(--cpd-color-icon-accent-tertiary);
-    margin-right: $spacing-4;
+    margin-right: var(--cpd-space-1x);
     vertical-align: middle;
 }
 
@@ -105,7 +105,7 @@ Please see LICENSE files in the repository root for full details.
     margin-right: 12px;
     border-radius: 8px;
     background-color: $system;
-    margin-top: $spacing-8;
+    margin-top: var(--cpd-space-2x);
 
     .mx_PollOption_popularityAmount {
         width: 0%;