UI-state adapter

WelcomeUiState.kt

sealed class WelcomeUiState {
    /**
     * Login state wrapper
     * @property value Login UI state
     */
    data class Login(val value: LoginUiState) : WelcomeUiState()

    /**
     * Register state wrapper
     * @property value Register UI state
     */
    data class Register(val value: RegisterUiState) : WelcomeUiState()
}