Do not remove modules before loading template
Do not remove modules before loading template

Exisiting operators are left in place when a template is applied, so leave
existing modules in place as well to keep behavior consistent.

Signed-off-by: Brianna Major <6a62c0472e857db5994824f147beeb095c78d3a5@kitware.com>

OpenChemistry/tomviz,OpenChemistry/tomviz,OpenChemistry/tomviz,OpenChemistry/tomviz