Upload CW721 Base Contract

Passing this proposal will upload the CW721 NFT base contract to the Osmosis chain. \n\n## Details\nThis proposal would upload the current version (v0.16.0) of the base CW721 NFT contract, enabling the minting of non-fungible tokens on Osmosis in compliance with the CW721 specification. \n\nThe base CW721 contract allows the minting of NFTs and contains the three components of the specification. \n\n* Base - Handles ownership, transfers and allowances of the tokens\n* Metadata extension - Allows the token to contain unique metadata\n* Enumerable extension - Allows the contract to publish the full list of tokens minted and make them discoverable. \n\nFull Documentation: https://github.com/CosmWasm/cw-nfts/tree/main/contracts/cw721-base\n\n## Release Version\n https://github.com/CosmWasm/cw-nfts/releases/tag/v0.16.0\n\n## Version of Compiler used\ncosmwasm/workspace-optimizer:0.12.9 \n\n## Checksum\nd5fa68c6dcf210fd14e556a21d2f7a4976933da33caa97348ad99e0ec4373d9f\n\nCommonwealth Thread: https://commonwealth.im/osmosis/discussion/10117-cw721-contract-upload-proposal