Make the "Masquerade as" link more visible

Fix formatting.

working on this

I have implemented the proposed style for the link. Please review!

Thanks @anirudhsingh19, that looks great!

Though, the .masquerade-as-user-link:hover CSS class doesn't seem to be in effect ... Perhaps the change could be that the white text turns slightly light-grey, to acknowledge the hovering?

Also, what do you think about my suggestion about placing the button at the top? Would that be difficult?

Also, the link gets inserted at the bottom of the page. Perhaps placing the link at the top of the page, under "Status messages" or at the very top of "Main page content" could be worth considering?

As an extra thing I didn't mention, the "Unmasquerade" is also a bit hidden, as a regular link in the menu. I wonder if that could be shown as a button as well, like "Masquerade"? If it's too difficult, it's not super important.
Thanks!