Namespace collision between modules

[joe-bowman]

The work by Andy in #103 #107 #120 to refactor query methods under the query package means that we end up with naming collisions between methods such as DelegatorValidators which is present in both distribution and staking.

This is blocking #143 (wholesale adding of queries).

As such, I suggest we split client/query into a separate package per module to avoid these collisions.