erigon: can use more than one NodePort

[cjorge-graphops]

It seems erigon enables multiple protocol versions simultaneously: i.e. ver 68 and 67, by default, currently, but it's configurable. It allows to configure a list of ports, instead of just the one, to match the list of protocol versions. Our chart currently enables protocol versions 68 and 67, but sets only one port, leading to the result of us having a NodePort only for one of the enabled protocol versions.

We need to support this adequately in both the chart and namespaces defaults