Split examples from real library projects

[mervyn-mccreight]

Description

At the moment the examples are mixed in different ways directly into the project itself:

1. as sub-project for the ktor-example
2. directly inside the tests of the core-library (see e.g. https://github.com/stuebingerb/KGraphQL/blob/cc6efaeb821d3075480caaf374ce21797309f799/kgraphql/src/test/kotlin/com/apurebase/kgraphql/server/NettyServer.kt)

This has drawbacks:

• dependency updates in the examples do not need to be released or be mentioned in the release-notes (who cares?)
• when publishing the dependency-graph all dependencies only used in the examples can safely be excluded
  • this easy for the ktor-example project, one can just exclude this sub-project
  • it's harder for the example directly in the test-sources of the core-library
• it's not easy to see which dependencies are only there for the examples

Solution proposals

Separate root-project inside the same repository

Create a new root-project named "examples", that contains all examples.
The core-library can be included using Composite Builds, to depend on the current code-state inside the repository instead of a published version.

Move examples to separate ``KGraphQL-examples` repository

Create a whole new project for the examples, that contains all examples.
This way the examples can only depend on actually released versions of the library though, but this isn't necessarily a bad thing anyways.