[New Feature] Copy as base64.

[xuxiaocheng0201]

This would be a convenient feature if it is possible to copy the selected hexadecimal text into base64 encoding.

[hajdam]

Hi. This should be relatively simple task to add this to convert data operation. I'll keep it for hacktoberfest for now if anyone might give it a try.

[hajdam]

Added as convert method in release 0.2.4