Adding block replay script to contrib/tools folder

[wileyj]

Adding the script used to perform block replays.

this is a standalone helper script, designed for debian based systems and should self-install/build everything needed to run.
storage requirements are a bit heavy, and it will cook eggs with how hot the cpus get.

commented and passed shellcheck.

some notes:
Requires ~73GB per slice, plus an extra ~400GB for the chainstate archive and marf DB
as of 02/2025:

• for 10 slices, total disk used is ~1.1TB
  • 149GB for compressed chainstate
  • 232GB decompressed marf db
  • 73GB per slice dir (1 dir per cpu)
• for 15 slices, this is about 1.46TB
• for 20 slices, this is about 1.8TB

for 10 cpus, the entire block replay will take around 14 hours depending on network speed. once the chainstate is downloaded/extracted the runtime is roughly 12 hours.

Recommended to run this in screen/tmux since it is a long running process.

[obycode]

This is great! 🙌