Fix #141, Accept hex values in command parameters

[heathdutton]

Describe the contribution
Fixes #141. Command parameters containing hex values (e.g. 0x880) raise ValueError: invalid literal for int() with base 10: '0x880' in MiniCmdUtil.assemble_payload, because int(items[1]) defaults to base 10. This blocks common cases like passing a MsgId to TO_LAB_ADD_SUBSCRIPTION.

The fix is one character: int(items[1], 0) auto-detects the base from 0x, 0o, and 0b prefixes and otherwise parses as decimal.

Testing performed

• Reproduced the exact ValueError pre-fix with --uint16=0x880
• Post-fix: --uint16=0x880 and --uint16=2176 produce identical payload bytes (0880)
• Confirmed decimal, negative, zero, octal, and binary literals all parse correctly
• python3 -m py_compile passes on the modified file

Expected behavior changes

• Behavior Change: --<type>=<value> command parameters now accept hex (0x...), octal (0o...), and binary (0b...) prefixes in addition to decimal.
• Minor tradeoff: zero-padded decimals like 007 no longer parse (base-0 rejects them). Not a documented convention in this repo, and Python 3 itself forbids it in source literals.
• No API change.

System(s) tested on

• Hardware: Apple Silicon
• OS: macOS 15
• Versions: cFS-GroundSystem main

Contributor Info
Heath Dutton, Personal