fix: issue where polymorphism titles in refs wouldn't be surfaced

[erunion]

🧰 What's being changed?

This fixes a bug in how we generate JSON Schema for the Params component where under certain conditions, title properties on polymorphism schemas (oneOf, anyOf, and allOf) would be deleted.

This also patches in a workaround for a bug in RJSF where if a title property is within a $ref and not at the level of the $ref, it wouldn't be used when constructing a dropdown for the schemas, instead displaying a placeholder label of "Option 1". Bug ticketed here.

🧪 Testing

You can see this bug in action here: http://bin.readme.com/s/5f46ce04c46abe00244f41f6

Though the Cat and Dog schemas have a title property, it's not used in the dropdown.

With this fix, it now looks like:

[domharrington]

Meat of the changes here: readmeio/oas@9770803#diff-9d1566fd5ed80afc032acefe10aff044

LGTM!

[darrenyong]

Tested this with polymorphism.json as well as the Swagger files of the customers that were experiencing this issue and adding title under the $ref components correctly renders the title rather than having Option 1, Option 2, etc.