slicedimage uses sptx-format validator to validate input images

[ambrosejcarr]

slicedimage should outsource validation to sptx-formats, allowing us to keep any refactoring of spec-related changes to one place.

ACs:

• slicedimage imports sptx-format
• all validation occurs in imported tool.

[joshmoore]

My understanding is that this is no longer accurate?

[ambrosejcarr]

I believe we are deferring a decision on this. The most important things are currently:

• validation occurs somewhere
• dependencies between repositories are clear
• sptx-format, starfish, and slicedimage have consistent code states (suggested implementation: through pinned versioning)

[joshmoore]

s/no longer accurate/postponed/ in the sense that a PR for making this repo depend on sptx-format is not immediatelysloted. 👍