Improve runtime performance

[orsinium]

No description provided.

[orsinium]

2-3 times faster now, with a bit slower decoration. Good.

Before:

# import
  5kk loops, best of 5: 82.244 ns

# CLASSIC CONTRACTS
# decorate
  20k loops, best of 5: 13.685 us
# call
  200k loops, best of 5: 980.015 ns
# call with args
  200k loops, best of 5: 1.644 us
# contract error
  20k loops, best of 5: 11.129 us

# VAA SIMPLE
# decorate
  10k loops, best of 5: 25.485 us
# call
  20k loops, best of 5: 11.328 us
# call with args
  20k loops, best of 5: 19.045 us
# contract error
  20k loops, best of 5: 13.434 us

After:

# import
  5kk loops, best of 5: 82.693 ns

# CLASSIC CONTRACTS
# decorate
  20k loops, best of 5: 16.98 us
# call
  500k loops, best of 5: 688.965 ns
# call with args
  200k loops, best of 5: 1.171 us
# contract error
  50k loops, best of 5: 4.212 us

# VAA SIMPLE
# decorate
  10k loops, best of 5: 26.283 us
# call
  50k loops, best of 5: 4.106 us
# call with args
  50k loops, best of 5: 6.486 us
# contract error
  50k loops, best of 5: 5.627 us

[orsinium]

Made decoration 3 times faster as well by deferring init of everything that can be deferred. Also, read signature once. lru_cache stays, it helps if there are multiple contracts for one function.