[WIP] Display friendly content type name in admin

[jorrit]

Also refactors content type name fields in config service

Summary

I noticed that the content type field in the 'add item' dialog shows an 'unfriendly' content type name. I've refactored the code to use info.displayName.

The ConfigContentTypeDTO type contained quite a few fields related to the name of the content type:

• name
• label
• labelSingular
• contentTypeName

There seems to be redundancy between these fields. One of the purposes seems to be to build the GraphQL type name. I've tried to reuse the logic from @strapi/plugin-graphql to do this work instead of doing this in the pluign.

Test Plan

This change is a work in progress and untested. I made these changes as a suggestion. I hope the changes can be tested and refined by the maintainers. Thanks in advance!

[SalahAdDin]

@jorrit man?