Fix StateMetadataOutput's constructor not setting the stateMetadata field

[thibault-martinez]

No description provided.

[schierlm]

In case you want to complete other fields "forgotten" by other constructors of types (indirectly) referenced by block Payload subclases (as of 1.1.1-WASM), you can check

https://github.com/iota-laboratory/iota-laboratory.github.io/blob/03fd537e0a5d3be7d40b5b6a9657356b87cf4652/block_payload_types.js#L3-L178

for cf: (constructor fields) values:

• TreasuryTransactionPayload: No exposed constructor at all, but the hidden one has all fields
• AliasOutput: Misses (after this commit) nativeTokens, features, immutableFeatures
• BasicOutput: Misses nativeTokens, features
• FoundryOutput: Misses nativeTokens, features, immutableFeatures
• MigratedFunds, NativeToken: No exposed constructor at all
• MilestonePayload: Exposed constructor has no fields at all
• NftOutput: Misses nativeTokens, features, immutableFeatures

There is no urge to do that from my side, though. My workaround to dynamically tweak creation of those objects by setting the properties manually works fine for now.

// cc: @Thoralf-M