Display Widget child or String message based on specified direction for
specified duration
Build Context context is required to be passed
Either child or String message will be displayed and If both passed child
will be displayed, for passed Duration() value to duration parameter.
direction will define from where Widget needs to be displayed on the screen.
Value ToastDirection.top will display from top & ToastDirection.bottom will
display from bottom.
Passing TextStyle value to messageTextStyle will be used to style passed String message
& override default TextStyle specified for it.
Color value to messageContainerColor will take effect only when String message is
passed & override default backgroundColor specified for it. Default color is
Theme.of(context).primaryColorDark.
textAlign will handle alignment of message displayed in Toast.