Copy Array Element Button

[Mattes1000]

Added a copy button to the "control_holder" of an array. If the option "enable_array_copy" (default = undefined = false) is set to true, the button is visible.

PS: the options hide_delete_buttons, hide_move_buttons, hide_add_button can´t be overwritten if they are set as initial option.

[TrevorPage]

@Mattes1000 thanks for doing this. @jdorn is there a plan to merge this PR in soon? Would I need to use this branch or pull it into my own fork if I want to use the feature?

[illeszsolt]

I know this is an old PR, but it would be a useful feature.