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/Sources/Screens/Authentication/LoginScreen/View/LoginScreen.swift

@@ -76,7 +76,7 @@ struct LoginScreen: View {
                 Text(L10n.commonUsername).foregroundColor(.compound.textPlaceholder)
             }
             .focused($isUsernameFocused)
-            .textFieldStyle(.elementInput(accessibilityIdentifier: A11yIdentifiers.loginScreen.emailUsername))
+            .textFieldStyle(.authentication(accessibilityIdentifier: A11yIdentifiers.loginScreen.emailUsername))
             .disableAutocorrection(true)
             .textContentType(.username)
             .autocapitalization(.none)
@@ -89,7 +89,7 @@ struct LoginScreen: View {
                 Text(L10n.commonPassword).foregroundColor(.compound.textPlaceholder)
             }
             .focused($isPasswordFocused)
-            .textFieldStyle(.elementInput(accessibilityIdentifier: A11yIdentifiers.loginScreen.password))
+            .textFieldStyle(.authentication(accessibilityIdentifier: A11yIdentifiers.loginScreen.password))
             .textContentType(.password)
             .submitLabel(.done)
             .onSubmit(submit)
@@ -99,7 +99,7 @@ struct LoginScreen: View {
             Button(action: submit) {
                 Text(L10n.actionContinue)
             }
-            .buttonStyle(.elementAction(.xLarge))
+            .buttonStyle(.compound(.primary))
             .disabled(!context.viewState.canSubmit)
             .accessibilityIdentifier(A11yIdentifiers.loginScreen.continue)
         }