ConvSym: Dedup offsets in `log` and `asm` parsers

[vladikcomper]

Support additional options for offset deduplication in log and asm parsers.

Currently, deb1 and deb2 parsers implement /favorLastLabels(+|-) option to resolve cases where several symbols share the same offset.

For convenience, a similar option should be also added to log and asm parsers, but it should be an opt-in feature (old behaviour should still be supported by default)