BCI-1511: only contract schema changes

[augustbleeds]

Originally diffed from #355 to just seperate out the schema changes

Changes:

• For query messages use serialized objects instead of enums (ex: { "owner": {} } instead of "owner" to query the owner of a contract) for best practices + type generation compatibility
• Modify schema generation script to use new write_api! macro. It creates a main .json file which describes the entire contract json api and raw/ file folder which contains individual json schemas
• Add main .json cw-plus files in gauntlet-cw-plus package

TODO: make changes to gauntlet to support the query message types (in a later PR)

[archseer]

Hmm why the need for this? The crate's readme specifically states it's a dev dependency

[augustbleeds]

https://book.cosmwasm.com/basics/good-practices.html#json-schema -- just copied over here. It also didn't work as a dev dependency as I wasn't able to use it in schema.rs

[archseer]

LGTM, it does look like the schema conventions changed slightly (so no more dev dependency, custom macros)