Added table copy all functionality to Pimcore

What was the issue? 

The tables didn't have the copy option, and if we wanted to copy the data from one table to another, we'd have to copy each piece of data separately.

How did you solve it? 

I added a button that opens a window in which all of the data from the table is gathered. From that window, we can manually select and copy the data, or click the button "Copy" and copy all of the data instantly.

Why is this fix important?

The main reason why this fix is important is that it speeds up and facilitates the process of copying data from one table to another.

How does it feel to contribute to a platform such as Pimcore?

It feels great because this contribution won't help just me, but also all the other developers working with Pimcore. 

And if you want to check out this pull request, just follow the link!