eed48a7322 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
5e9dba822d