Copy-paste data variables

[kof]

1. Right now you can't copy and paste a data variable easily.

2. There is only copy resource button, but it copies the curl text only, not the entire variable. Additionally the position of that copy resource button makes it assume the variable will be copied, but then user pastes the curl text onto canvas and is surprised it doesn't work. Tooltips don't solve the problem as nobody reads them.

   

Todo

1. Add copy action to the data variables list menu

   

2. Allow pasting data variables anywhere in the builder when instance is selected

3. Move the copy button in the resource dialog to somewhere else inside that resource panel, so that its clear its about that resource specifically and not global for the variable, probably better call it "Copy cURL" instead of generic icon, below the section is probably fine