refactor: Various refactoring chores

Explanation of Changes

Proxy Contract has been renamed to Core Contract
Removed remnants of staking and data request contracts as we migrate to mono contract structure
Wasm types have been refactored. There are now three wasm types: Data request (which includes both data request and tally wasms), data request executor, and relayer. Note that the transaction tx wasm-storage store-data-request-wasm no longer takes a wasm type flag.

Closes: #279 Closes: #277