[aptos-node] Tune local testnet parameters
[aptos-node] Tune local testnet parameters

I've decreased a bunch of the polling timeouts and concurrency amounts
to decrease the CPU overhead of a local testnet.  On my M1 mac the
decrease in overhead is from >800% to ~250%.

aptos-labs/aptos-core,aptos-labs/aptos-core,aptos-labs/aptos-core,aptos-labs/aptos-core,aptos-labs/aptos-core,aptos-labs/aptos-core,aptos-labs/aptos-core