feat(dogfood): load genesis state

[MaxMustermann2]

The x/dogfood module should load the genesis state from disk for the network to successfully bootstrap with the rPOS process. This pull request makes that happen. The genesis state of this module is described as the parameters of the module as well as an initial list of consensus public keys with their vote powers. This list is forwarded to Tendermint.

The genesis state is structured as follows:

{
    "params": {...},
    "initial_val_set" [
        {
            "public_key": "0x...",
            "power": "123456"
        }, {...}
    ]
}

The stateful validations performed are:

• The epochs parameter is registered in the epochs keeper
• The list of asset IDs provided as a param are registered staking assets.
• There is a registered operator for each consensus public key in the initial validator set.

The stateless validations are listed below.

• The number of initial validators does not exceed the max. (If the number of validators provided is 0, the validation does not fail; rather, an empty validator set is forwarded to Tendermint which complains instead).
• There are no duplicate public keys in the provided validator set.
• The public keys provided are valid and can be converted from the bytes32 format to the Tendermint public key.
• The vote power for each public key is non-negative.