SIP-033 The Generalized Standard for non-custodial Marketplace traits

[314159265359879]

Here is a very early draft PR of what a more generalized standard for non-custodial marketplace traits could look like.

Before this can be send to the CAB's I would suggest this be thoroughly reviewed edited by clarity experts and tested by one or more of the existing marketplaces on Stacks for tradeables such as gamma.io or tradeport.xyz.

Where SIP011 is simple and allows listing of NFT's only in microSTX (STX). A standard already widely used.

This standard is envisioned for listing of any Standard token (SIP009 (NFT), SIP010 (FT) and SIP013 (SFT)) and setting a selling price in any of those standard tokens too. buy-in-token rather than "buy-in-ustx".

[314159265359879]

Changed the name to SIP-033 to prevent confusion with the stack-extend bug fix SIP.