Remove DesignKit package (#1886)

- Move button styles to Compound
- Rename text style to AuthenticationTextStyle as its only in the auth flow.
- Add the brand colour locally for now until its included in Compound.

* Update snapshots.

---------

Co-authored-by: Stefan Ceriu <stefan.ceriu@gmail.com>

ElementX.xcodeproj/project.xcworkspace/xcshareddata/swiftpm/Package.resolved

@@ -13,7 +13,7 @@
       "kind" : "remoteSourceControl",
       "location" : "https://github.com/vector-im/compound-ios",
       "state" : {
-        "revision" : "0966ff92b2670e3a96259c87016edd92d7ea7797"
+        "revision" : "3daf2cc662eb10181cf15d717745e0f2ba744372"
       }
     },
     {
@@ -43,15 +43,6 @@
         "version" : "1.7.18"
       }
     },
-    {
-      "identity" : "element-design-tokens",
-      "kind" : "remoteSourceControl",
-      "location" : "https://github.com/vector-im/element-design-tokens.git",
-      "state" : {
-        "revision" : "63e40f10b336c136d6d05f7967e4565e37d3d760",
-        "version" : "0.0.3"
-      }
-    },
     {
       "identity" : "emojibase-bindings",
       "kind" : "remoteSourceControl",