Pass Config to wasmvm and make WasmLimits available to contract dev

[chipshort]

requires #1981

• provide a way to x/wasm users to pass in the Config implemented in Implement Config that is passed from wasmd to cosmwasm-vm wasmvm#559
  • it contains the contract memory limit, the memory cache size from the existing WasmConfig and also the availableCapabilities and the path for the base directory of the cache (currently this is the homeDir provided by the user suffixed with "/wasm").
  • we don't necessarily have to expose the Config to the user. They could also just pass the parts (as is done now) and we build the Config from that. But exposing it makes it easier to extend in the future.
• provide a WasmLimitsConfig query for the WasmLimits inside the config that returns it as a json string such that users have a way to get the config from the chain. This is needed such that contract developers can provide it to cosmwasm-check
  .
  • Note: If there is a better way to do this than a query or we rename this then that's fine, but we need to adjust the cosmwasm-check help text.