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.

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

ElementX/Sources/Screens/Authentication/ServerConfirmationScreen/View/ServerConfirmationScreen.swift

@@ -58,7 +58,7 @@ struct ServerConfirmationScreen: View {
             Button { context.send(viewAction: .confirm) } label: {
                 Text(L10n.actionContinue)
             }
-            .buttonStyle(.elementAction(.xLarge))
+            .buttonStyle(.compound(.primary))
             .accessibilityIdentifier(A11yIdentifiers.serverConfirmationScreen.continue)
             
             Button { context.send(viewAction: .changeServer) } label: {