show select/unselect all buttons within the dropdown list

[blaazetech]

please create an option for the bootstrap select, which will help all of us to internally use this featureflag to just show or hide the buttons, as of now we are using external buttons with tagging and other extra codes, if you provide the above said feature, it will save most of the user's time, and also try to make it suitable and workable on mobile also, as per my calculations it will be hard to get the ui elements for mobile using the native functionalities, but please try.