Wire up the DSL for aliases

[TheMrMilchmann]

The API for SchemaAlias is fully fleshed out already but the backend has yet to be implemented. This is probably the last major missing feature and must definitely happen before 0.7.0.

api-generator/src/main/kotlin/com/gw2tb/apigen/internal/dsl/schema.kt

Lines 37 to 39 in 96e7165

	internal fun Alias(type: DeferredPrimitiveType, name: Name): DeferredPrimitiveType {
	return type // TODO impl
	}