Improve faucet UX

[elboletaire]

Right now the faucet shows a toast as soon as you return back from the oAuth provider saying "Claiming your tokens, please wait".

I've been waiting for a minute or two since I realized I had to sign the transaction (metamask didn't pop-up initially).

At least a different toast should be shown when waiting for the user signature, but also, maybe this process could be shown in a modal like we do in other places like during the process creation.

A modal showing a two step process of "sign request" and "claiming tokens" would be enough.