Update knwon_hashes.py

[kirtixs]

This pr updates hashed method names.

The hashes have been downloaded from https://www.4byte.directory/ and can be used in combination with any license as per their tos. A new util script has been added that automatically downloads the hashes from the site and saves them in a specified location.

Hashes that were present in known_hashes.py and not in 4byte.directiory have been submitted. As a positive side effect duplicate or bad methods have been removed from the list.

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[joshwatson]

Thanks for the contribution! We're actually in the middle of a refactor of ethersplay, and knownHashes is moving to a different module, but we'll probably add the new methods from this into that module!

[kirtixs]

Thanks for letting me know. In the meantime, could you accept this pr until refactoring has finished. It would probably help a few users.