feat: allow to set default InputValueSerializer

[dwilkolek]

Extended GraphQLProjection to allow setting custom InputValueSerializer per thread.
This change will allow to use any scalars with DgsClient client and setup them once.

@Test
fun test() {
    InputValueSerializerProvider.serializer = InputValueSerializer(
        mapOf(UUID::class.java to UUIDScalar.INSTANCE.coercing)
    )
    /* line below would fail before */
    val query = DgsClient.buildQuery {
        movies(filter = UUID.randomUUID())
    }
}

closes #455

[srinivasankavitha]

cc @mbossenbroek

[mbossenbroek]

Thanks @dwilkolek for adding this! 👏

[dwilkolek]

No problem, I find this project fascinating. I'll keep an eye for good first issues 😉