Blender Git Loki

Cleanup: Avoid error prone pointer storage in SnapObjectParams

eed48a73222efb86b53cdd99079f8c26eba30e57 caused the `SnapObjectParams` to be stored in the `SnapObjectContext`.

As this pointer is always passing in stack memory, so it seems error prone to keep a reference to this in `SnapObjectContext` since failure to set this will reference undefined stack memory.

So avoid this by moving params out of `SnapObjectContext`.

Differential Revision: https://developer.blender.org/D13401