exploration: cache the results of individual calls and reuse them instead of re-executing

[bertmiller]

Right now rbuilder executes every transaction individually. Many bundles either share the same transaction, or they have transactions that share individual calls or precompiles across them - e.g. 2 different txs call the keccack precompile with the same input. We should explore how we can smartly cache and reuse results across transaction execution instead of re-executing.