feat(res): support 16-bit entry offsets

[pubiqq]

Fixes #2267

[skylot]

Hm, with sample provided in #2267 (comment) parsing fail at closest

is.checkPos(entriesStart, "Expected first entry start");

because of additional 2 bytes, maybe it is padding, so it might be better to change this line to

is.skipToPos(entriesStart, "Failed to skip to entries start");

And, as soon as, sample also use compact entries, it still can't be parsed, so I am not sure if this is a correct solution.
To be honest, it is better to merge this PR with compact entries support, because this is the only way to verify its correctness.

[pubiqq]

This PR only adds support for 16-bit entry offsets. Not support for compact entries, not support for non-standard paddings, only 16-bit entry offsets.

But if you insist on implementing all together, then you can close the PR. I don't think I'll create a PR with compact entries support, because my current implementation of the resource parser is too different from yours.

[skylot]

I see.
I will try to implement compact entries support myself and will merge this PR once I managed to parse provided sample.