feat(packets): add many new packets

fix(packets): make UpgradeRare packet deserialize correctly

feat(packets): add PerparedLevel to PacketStringEnumerator's levels to allow multiple prepared levels for nested packets

chore(packets): add documentation for ski packet

fix(packets): make generator work with packets that have 0 members

fix(packets): make UpgradeRareSubPacket converter work with "0"

fix(packets): make bs packet effect id nullable

chore: update versions

feat(packets): make skill vnum in su packet nullable

fix(packets): add header for st sub packet

chore: bump versions to support new PacketSerializer

chore: update PacketSerializer version

fix(packets): add missing usings

feat(packets): do not add the same packet multiple times

chore: move PacketSerializer types to correct namespace

feat(packets): add support for st buff vnums with levels

Merge pull request #32 from Rutherther/combat

Add combat extension

chore: update versions

fix(packets): parse 0 UpgradeRareSubPacket as 0, 0

fix(packets): Add new unknown field to ski packet, make rank of SkiSubPacket optional