Autoformat pasted MAC address on adapter configuration dialog

[prischnikov]

For my home lab, I usually use the same MAC addresses for creating my VMs after reinstalling the host (bridged adapters)

To set the VMs up faster, I want to be able to copy-paste that information from my static DHCP config file to the MAC address field. The format in the DHCP config file is like AA:BB:CC:DD:EE:FF but VBox does not accept the ":" character. When pasting such a string with CTRL+V into the MAC address field, it should accept the string and automatically remove the ":" characters