bug: DecimalLiteral.MarshalBinary produces incorrect results

[ella-chao]

Apache Iceberg version

main (development)

Please describe the bug 🐞

There are two issues with this function:

1. The carry from the increment here is lost, so given the input -256 for example [0xFE, 0x00] is returned instead of [0xFF, 00].
2. The min bytes calculation here is wrong for -2^7, -2^15, etc. These fit in one fewer byte than what minBytes is reporting.