* 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>
# Conflicts:
#	les/handler_test.go
#	les/peer.go
#	les/protocol.go
#	les/server_handler.go
#	les/test_helper.go