Interaction reference count decremented too aggressively

[bvaughn]

Under certain conditions we decrement the __count attribute too often, which can result in onInteractionScheduledWorkCompleted being called prematurely and/or more than once for a given interaction.

• Track interactions scheduled during (sync) render phase.
• Do not double-decrement suspense loads within a sync render.
• Do not decrement sync commits that are waiting on suspense when the Placeholder is past its expiration.
• Properly decrement pending interaction count when a suspense resource loads before its placeholder is shown.
• Add test with high priority render between suspended and resolved suspense states (for both sync and async rendering)