resolve ban-types eslint-disables

I disabled `ban-types` since it was detected in the eslint upgrade.  I will make an issue to go through these instances, uncomment ban-types, and apply the changes required by the linter.

_Originally posted by @3xtr4t3rr3str14l in https://github.com/ChainSafe/simpleserialize.com/issues/43#issuecomment-875120437_