feat(FileIO): Adds user extensible FileIO

[BlakeOrth]

• Stubs out the initial required items to build a backwards compatible FileIO extension

Based on the discussion in #172 it seemed like a backwards compatible FileIO extension may be the desired path to allow user extensible implementations for FileIO operations. I often find it difficult to fully grasp how any given change may need to trickle through the existing codebase, so I wanted to do a quick implementation to help move along any design around extensible FileIO. I figured building a concrete implementation as a draft so the community can provide feedback would be a good path forward. Given the discussion, feedback from @Xuanwo is likely needed, as well as any others who'd like to chime in.

[Xuanwo]

Thank you @BlakeOrth for this PR, I will visit code and try to find the migrate path.