UI updates to fit more services

[chasefleming]

There are now a lot services that are listed in Discovery and more are coming. There is currently a scroll for the iFrame/rpc, but we need a more versatile and better looking solution across other methods like pop/rpc and tab/rpc for when a large number of services are listed. We need a UI update to address this.

This also needs to address the issue of layout for when a service may have multiple sub-services (e.g. WalletConnect has different pairings for each wallet).

[cybercent]

We did a mockup for inspiration, to reduce the header size and leave more space for the wallet list.

[chasefleming]

@cybercent this looks great. There might be a larger redesign down the road -- but not sure when that will be -- so this looks like a nice way to solve the problem in the mean time using a lot of the elements we already have. I like it.