R1:0203105a94e3

Add more selectors to existing "bin/worker" commands

Summary:
Ref T13591. Add more selector flags to let "bin/worker" commands operate on tasks by container PHID, object PHID, priority, etc.

This anticipates adding "bin/worker reprioritize" and "bin/worker delay" workflows, to provide more tools for handling repository imports.

Test Plan:
- Ran `bin/worker execute`, `cancel`, `retry`, and `free` with various sets of selector flags.
- Used `--min-priority`, `--max-priority`, `--object`, `--container`…