Make username visible

[l-br1]

Make the username visible either on the sidebar or on the page

[vpaunovic]

@MSzalowski Our idea (mine and @teske00 ) was presented long ago for this and I think you agreed on that. Idea was:

• On GovTool side create state (for example pdfUsername and setPdfUsername) and pass that down to PDF pillar. And then, when user create or login - we just call that function and it will be visible/reachable on GovTool side so it can be placed as a card on top of wallet and drep info card in sidebar.

What do you think?