Add ton-storage namespace codec

[TONresistor]

Add a ton-storage namespace codec for TON Storage BagIDs.

Code	Name	Tag	Payload
0xb79910	ton-storage	namespace	32-byte TON Storage BagID

TON ADNL addresses already have a dedicated multicodec allocation:
adnl (0xb69910), added in #402.

ADNL addresses are address-based identifiers for TON network endpoints. TON
Storage BagIDs are content-based identifiers derived from a bag's TorrentInfo
cell. Although both are 32 bytes, they require different resolution flows, so
this PR adds a dedicated ton-storage codec instead of reusing adnl.

TON Storage is TON's distributed file storage network. Files are organized into
bags, each identified by a 256-bit BagID.

A BagID is the 32-byte representation hash of the bag's TorrentInfo cell. It is
the native identifier used by TON Storage clients and by TON DNS
dns_storage_address records.

Binary payload:

bag_id[32]

When used as an ENSIP-7 contenthash:

uvarint(0xb79910) || bag_id[32]

The canonical user-facing URI is:

tonstorage://<64-hex-character BagID>

This allocation enables TON Storage BagIDs to be represented as self-describing
content addresses, including in ENSIP-7 contenthash records.

Existing implementations and clients include:

• ton-blockchain/ton
• xssnick/tonutils-storage
• xssnick/TON-Torrent

Sources:

• TON Storage documentation
• TON DNS standard