Investigate dagger-spi for inject validation and type resolving

[alex2069]

As of 2.15 Dagger includes an SPI allowing for graph introspection at compile time.

This could allow DevFun to know where/how to obtain instances, and as to whether a type can be provided at all (rather than at present; reflectively checking type information of fields/functions).

• Known issue: The interface definitions changed at 2.15 > 2.16 and are not backwards compatible. Support would be for, at present, only Dagger 2.16.