support SortOrderInput for typegraphql

[davidmwhynot]

v0.27.0 of typegraphql-prisma bumped prisma up to v5 wherein orderByNulls is enabled by default. This causes a breaking change in the emitted schema due to the type of the sort input type values being either SortOrder or SortOrderInput depending on if the field being sorted on is non-nullable or nullable respectively. This implementation addresses that breaking change and should be backwards compatible as it allows for either of the two options to be used based on the introspection results.