Account for potential overflow of various tags

[dktapps]

The maximum possible size of a TAG_ByteArray's payload is 2GiB, but this is not currently capped by the library. While this is a less immediate problem than the old StringTag bug, this also needs to be catered for.

This is also a problem for TAG_List and TAG_IntArray since this uses a 4-byte integer prefix to store length as well.