* les: refactored server handler

* tests/fuzzers/les: add fuzzer for les server handler

* tests, les: update les fuzzer

tests: update les fuzzer

tests/fuzzer/les: release resources

tests/fuzzer/les: pre-initialize all resources

* les: refactored server handler and fuzzer

Co-authored-by: rjl493456442 <garyrong0905@gmail.com>

* tests/fuzzers/abi: better test generation

* tests/fuzzers/abi: fixed packing issue

* oss-fuzz: enable abi fuzzer

* common,crypto: move fuzzers out of core

* fuzzers: move vm fuzzer out from core

* fuzzing: rework cover package logic

* fuzzers: lint

This PR adds re-written difficulty calculators, which are based on uint256. It also adds a fuzzer + oss-fuzz integration for the new fuzzer. It does differential fuzzing between the new and old calculators.

Note: this PR does not actually enable the new calculators.

* added bls fuzzer

* crypto/bls12381: revert bls-changes, fixup fuzzer tests

* fuzzers: split bls fuzzing into 8 different units

* fuzzers/bls: remove (now stale) corpus

* crypto/bls12381: added blsfuzz corpus

* fuzzers/bls12381: fix the bls corpus

* fuzzers: fix oss-fuzz script

* tests/fuzzers: fixups on bls corpus

* test/fuzzers: remove leftover corpus

Co-authored-by: Marius van der Wijden <m.vanderwijden@live.de>