* core: use uint64 for total tx costs instead of big.Int
* core: added local tx pool test case
* core, crypto: various allocation savings regarding tx handling
* Update core/tx_list.go
* core: added tx.GasPriceIntCmp for comparison without allocation
adds a method to remove unneeded allocation in comparison to tx.gasPrice
* core: handle pools full of locals better
* core/tests: benchmark for tx_list
* core/txlist, txpool: save a reheap operation, avoid some bigint allocs
Co-authored-by: Martin Holst Swende <martin@swende.se>