Partial Set Security: Introduce new filters for validators

[insumity]

Introduce new filters for validators so we can have the following:

1. Cap validator power. For example, we can cap validators' power to 1% which means that if a validator has 3.7% power on the Hub, only 1% of this power would validate the consumer chain.
2. Cap validator set. A consumer chain might desire that at most m validators can validate it at any point in time.
3. Allowlisting/Denylisting. A consumer chain can decide on which validators are allowed to validate it and which are not.

The first filter can work irrespectively of whether the chain is Top N or Opt In. With the other two filters this is not the case. For instance, can we cap the validator set with Top N, etc.