Support for loading apollo modules through SPI

[zth9]

The current method of loading Apollo Module is fixed and difficult to expand.
Can we support for loading apollo modules through SPI?

[nobodyiam]

There are several places for customizing the modules, which, in my opinion, could be suitable for most scenarios.

1. The injector itself is loaded via SPI.
2. The default injector features a ApolloInjectorCustomizer mechanism.

Could there be a situation that I've overlooked?