Add copy column to transaction view

Adds copy button to the transaction view. 

I missed the fact that the other views have a button that copies the address to the clipboard! In my opinion the copy button is not very intuitive. It's not immediately obvious what it does: Copy the address to the clipboard? copy the balance /  amount or something else? It has a mouse over explanation but the text is invisible when the row is selected.

After 15 years of using web apps, it's strange that everything is not selectable / copy pastable. So if I could choose, I would do away with all the copy buttons and make all the addresses / amounts selectable. Would you accept a pull request that did that to all the views?