Launchpad v2 - NFT Contract

Launchpad v2 - NFT Contract\n\nIn this update SG721 contract unlocks new functionality to creators like updating collection information, allowing to set an optional trading start time with a max offset set by governance, signaling a collection as explicit, allow royalty updates (only to reduce them).\n\nThe source code is available at https://github.com/public-awesome/launchpad/releases/tag/v0.16.0\n\n\nCompile instructions\n\n```\ndocker run --rm -v "$(pwd)":/code \

--mount type=volume,source="$(basename "$(pwd)")_cache",target=/code/target
--mount type=volume,source=registry_cache,target=/usr/local/cargo/registry
cosmwasm/workspace-optimizer:v0.12.8\n\nThis results in the following SHA256 checksums:\n71e2a5f2ca5503aaaf10f835ad54d60006660e49a86b16f95442c3fdb87a73e6 sg721_base.wasm\n\n# Verify on chain contract\nstarsd q gov proposal $id --output json
| jq -r '.content.wasm_byte_code'
| base64 -d
| gzip -dc
| sha256sum\n\n\n# Verify local contract\nsha256sum artifacts/sg721_base.wasm\n\n```\n