[Meshery Models] Create SubCategories

[leecalcote]

Current Behavior
Models only have Categories.

Desired Behavior
Add support for SubCategories.

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Resources

Alternatives / Additional Context

[adityaofficial10]

@leecalcote Can I take this up?

[leecalcote]

@adityaofficial10, thanks much for jumping in and volunteering. In an effort to help guarantee your success in undertaking assignment of the issue, will you:

1. confirm that you're able to build the project, specifically, the components necessary to resolve this issue.
2. confirm the approach you intend to take to resolve the issue.

[adityaofficial10]

1. I've built meshkit so far on my local. I think I'm gonna need schemas repo as well.
2. What I can see is, there's a subcategory entity represented as a pure string in the schemas repo. We'd have to add support for SubCategory there and then nesting it within Category there. Then we will have to add the endpoint here at:endpoints with the support.

Once done, I can test this with meshery server..
Would love to know your thoughts..