IntroduceIdentityPage: Resolve TODO of not hardcoding URIs
- Move the getURI() to the GetPuzzleWebInterfaceToadlet since there is no parsing code for that URI in the IntroduceIdentityPage, i.e. the code which is addressed by that URI is in the Toadlet.
- We cannot make the getURI() in the Toadlet static though so we still need the getPuzzleImageURI() in IntroduceIdentityPage