sync validations between different `token metadata` componentts

[mtsitrin]

currently we have a few places that use the token metadata:

1. x/denommetadata
2. vfc
3. x/rollapp on rollapp registration

the validation scheme should be the same, as they all need to pass for successful registration.

e.g this case, passes the rollapp creation but fails on vfc registration

[
    {
        "description": "rollapp rollappevm_1234-1 native token",
        "base": "urax",
        "denom_units": [
            {
                "denom": "urax",
                "exponent": 0
            }
        ],
        "name": "rollappevm_1234-1 urax",
        "symbol": "URAX",
        "display": "urax"
    }
]