Make it possible to disable use of auxiliary EVM store (aka receipts_db)

[enlight]

Everything currently being written to receipts_db isn't necessary for consensus, so it should be possible to disable all writes to this DB on certain nodes. The receipts are only really needed on the nodes that handle queries from users.

[pathornteng]

Can we just set maxReceipts to 0?

[enlight]

Dunno, but it's not just receipts we need to disable, everything else that's stored in that DB needs to be disabled too, bloom filters, tx hash index, etc.