update all shebangs and examples to point to python3
use the pre-parsed rec files as we don't gain anything by forcing CI to run tshark
if any future test cases want to be added they can generate an appropriate rec file with the following command:
tshark -r <pcap> -T fields -e data | xxd -r -p
pycrypto is really busted so this change also replaces it with pycryptodome (a mostly drop-in replacement)
python3recfiles as we don't gain anything by forcing CI to run tsharktshark -r <pcap> -T fields -e data | xxd -r -p