addURL function is missing in asset.param library

[meetthosar]

While working on a fork of the algorandfoundation/hashi library to add APIs for the "Create Asset" functionality, I encountered an issue. Using the updated version of algo-model, I noticed that the AssetParamsBuilder class does not include the addUrl function, which is needed when building asset creation transactions with AlgorandTransactionCrafter.

[PhearZero]

Good idea! Would you like to contribute? It should be simple to add the method to AssetParamsBuilder in the asset.params module