restore different point count N on solve graph, also fix test

[dehann]

          restore different point count N on solve graph, also fix tests:

IncrementalInference.jl/test/testVariousNSolveSize.jl

Lines 24 to 26 in 8610923

	@error "MUST RESTORE SOLVE WITH DIFFERENT SIZE N"
	if false
	# Change to N=150 AFTER constructing the graph, so solver must update the belief sample values during inference

Originally posted by @dehann in #1720 (comment)