Validate CLI seed and server port arguments

[FabioMalpezzi]

Summary

Reject a couple of invalid argument values before they can reach runtime setup:

• reject negative --seed values in ds4, ds4-agent, and ds4-eval
• reject ds4-server --port values outside the valid TCP port range 1..65535

strtoull() accepts strings like -1, which previously let negative seed input wrap into a large uint64_t. The server also accepted ports above 65535, which were later narrowed through the uint16_t cast used for htons().

Testing

make ds4 ds4-agent ds4-eval ds4-server
./ds4 --seed -1 --help
./ds4 --seed 0 --help
./ds4 --seed 18446744073709551616 --help
./ds4 --seed +1 --help
./ds4-agent --seed -1 --help
./ds4-eval --seed -1 --help
./ds4-server --port 70000 --help
./ds4-server --port +65535 --help
git diff --check
./ds4-eval --self-test-extractors
./ds4_test --server