Add categories for DeFi, Dex, Lending, Yield, Bridge Users

[steegecs]

Context: The purpose of this PR is to extend the accepted categories. Specifically, the Defi, Dex, Lending, Yield Farming, and Bridging categories have a description that is not broad enough to cover users of DeFi or some type of DeFi protocol. The definitions of these categories generally describe addresses that are a part of the functionality of a DeFi protocol and don't include users of them.

We want to be able to tag users who interacted with a protocol type or DeFi in general with a tag that better fits this description, and this PR adds those tags to the accepted categories.

[beingzy]

Context: The purpose of this PR is to extend the accepted categories. Specifically, the Defi, Dex, Lending, Yield Farming, and Bridging categories have a description that is not broad enough to cover users of DeFi or some type of DeFi protocol. The definitions of these categories generally describe addresses that are a part of the functionality of a DeFi protocol and don't include users of them.

We want to be able to tag users who interacted with a protocol type or DeFi in general with a tag that better fits this description, and this PR adds those tags to the accepted categories.

This new suite of categories could expand the usage of our database. And, it aligns with our principle that our taxonomy (set of categories) is adaptive and should evolve over time. I think before formally merging those new proposed categories, we should address the following: 1) We provide the written definition per proposed categories. e.g. defi_user indicates a user who had signed up or had actually made transactions ? 2) I think updating schemas/categories is critical? We should establish a formal procedure to decide on the updates of schema. However, rather than waiting for long-standing negotiation, I think we may introduce staged procedure to carry out a change over time. That said, we may introduce an "experimental" attribute to annotate proposed categories and enable their data can be circulated in our system.

Any thoughts @leozc @zhanwu @daerae @steegecs @dongyi1991

[steegecs]

1. We provide the written definition per proposed categories. e.g. defi_user indicates a user who had signed up or had actually made transactions ?

The description I created for defi_user is An address that interacted with a smart contract used for decentralized finance (DeFi) projects, including decentralized exchanges, yield farming, lending, and more. So for us, this means that the user has actually made a transaction that involves either a direct or indirect interaction with a smart contract used for carrying out some DeFi operation. This works analogously for the other labels that have been added. Happy to clarify this more in the description and/or discuss more on it.

[steegecs]

2. I think updating schemas/categories is critical? We should establish a formal procedure to decide on the updates of schema. However, rather than waiting for long-standing negotiation, I think we may introduce staged procedure to carry out a change over time. That said, we may introduce an "experimental" attribute to annotate proposed categories and enable their data can be circulated in our system.

What would the staged procedure look like? For now, its probably worth deciding who will be involved in the arbitration of this process and then a set of requirements before merging any PR to add/update categories to ensure they add value, are correct, clear, unique, etc.