contract standards rewrite meta issue

[austinabell]

There are numerous things that could/should be fixed when making state-breaking changes, so worth to batch and trying to do everything at once before asking anyone to migrate. This is not a final list, just going to start accumulating and indexing other issues:

• no_std and optimize size Implement no_std support for SDK #443 (somewhat optional, this isn't a state-breaking change, but better to do before)
• Switch mapping from using TreeMap -- it's incredibly unscalable for iterating through pagination nft_tokens return exceed gas limit error if starting index is high enough #800 owner_by_id updated from TreeMap to UnorderedMap #810
  • Alternatively, could change/implement a new ordered map that stores extra data to be able to paginate more efficiently, but ordering isn't part of the NFT spec
• Tweak gas usage using gas weighted function calls. This has been updated in 4.0 to be splitting unused gas evenly, but the static gas cannot be removed without being breaking and causes issues. Dynamic ft_transfer_calls in FT standard implementation #619 NFT contract standard: The hardcoded GAS_FOR_FT_TRANSFER_CALL and GAS_FOR_RESOLVE_TRANSFER doesn't work well sometimes #559
• Explore Revisit nft_resolve_transfer args #568
• Update macros to be derive macros Removing boilerplate from token_standards #422
• Explore NFT Approvals refunding after nft_approve has problems #775
• Fix NonFungibleTokenApprovalReceiver::nft_on_approve return type #1053
• Implement royalty standard maybe? I have no context on this standard near nft contract standards not complete #667
• Explore (NFT standard) Why is the owner_id hashed as the prefix in tokens_per_owner? #677 (perhaps worth changing the hash to be only the first 20 bytes to minimize costs?)
• Resolve inconsistency from NFT nft_resolve_transfer does not match NEP (approved_account_ids != approvals) #967
• Remove upgrade standard