Static analysis on schemas

[rafaparadela]

We should be able to perform static analyisis on schemas. The idea is that when uploading that schema to Catamorph, we should be able to warn the user if they're doing something that we know is wrong, or hint a different approach.

For this issue to be done, we need to:

• Create all the plumbing needed to create rules
• Define and implement rules

[diesalbla]

@rafaparadela Taking a quick look at some issues, I was wondering if you could give an example of a kind of error, or warning, that you had in mind when creating the issue. One example I can think of, which we have discussed, is to have a reference checker, that makes sure that whenever you have a reference to a type, that type is defined in the file. This is common in OpenApi, with the components section. Is that something you were thinking about?

[rafaparadela]

This issue was originally created in Marlow, and I moved it to here. So I would say that @pepegar is the original reporter.
I guess that the main goal for this issue is providing a mechanism to warn when some the schemas don't fulfill the rules defined by the own serialization system. For instance, incompatible naming, wrong number of fields, empty coproducts, idk, stuff like that. If we set a rules-engine to validate the schema before operating with it, then it would provide like more security.
@pepegar correctly if I'm wrong, please.