`plugin.diff.file|type` -> `plugin.detectChanges`

[samuelstroschein]

Proposal

Replace the nested diffing functions with top level functions.

• simplifies the API by removing nesting
• simple mental model detectChanges -> detectConflicts -> applyChanges(-> optionally resolveConflict)

-plugin.diff.file()
+plugin.detectChanges({ old, neu })

Context

The diff API with nested namespaces was introduced to let a plugin diff own snapshot types.

[samuelstroschein]

Given the simple(r) mental model of

1. A plugin detect changes
2. A plugin "reports" conflicts [in the detected changes]
3. A plugin applies [non-conflicting] changes

I probably prefer reportConflicts as plugin API than detectConflicts. Curious what others think