TypeORM integration plugin

I wonder whether TypeGraphQL should stay as the uniwersal framework that works with many libs or to be more integrated with the libs that the most of the devs would use, like TypeORM.

I am thinking about the automatic relations resolving feature that could use lazy relation wrapper mechanizm or [`typeorm-loader`](https://github.com/Webtomizer/typeorm-loader) for performance purposes.

The best way would be to create plugin system and create `@typegraphql/typeorm` helper package that would provide better integration. I have to investigate this way if it's possible.

Any ideas, guys ❓

The issue proposes a plugin system and an @typegraphql/typeorm helper package, with automatic relation resolving using lazy relation wrappers or typeorm-loader. Start by investigating TypeGraphQL's existing integration boundaries and the referenced TypeORM approaches. Done would require a decided integration design and defined package scope, which the issue does not yet specify.

Written by the indexing model from the issue text.