GHO addresses library

[sakulstra]

@miguelmtzinf noted that for avara it would be nice to have a GHO addresses directly accessible (not via assets library).

Putting them on Misc i was opposed, because:

1. it's a duplication of what we already have in assets
2. misc is used in almost every aave proposal and aave related ecosystem project. As solidity currently does not tree-shake interfaces / libraries at verification every addition bloats verification everywhere and creates noise on diffing.

That said, I think as a compromise - especially considering the growing importance of GHO - it could make sense to just create a seperate GHOMainnet, GHOArbitrum, ... and remove things like GHO, GSM, CCIP from Misc.

[eboadom]

As the main "unit" of address book are big enough subsystems, I'd say that probably makes sense to go that way