Unify extended unique key format with Python version and add `alwaysEnqueue` flag

[janbuchar]

• check out these for reference
  • Improve the deduplication of requests crawlee-python#178
  • Include whitelisted HTTP headers in the extended_unique_key computation crawlee-python#548
  • Unify separators in unique_key construction (| vs _) crawlee-python#1512
• it should be enough to add the flag and change the separator and field order