fix(navigation_state): revises the fix for legacy zoom levels
fix(navigation_state): revises the fix for legacy zoom levels

This revises the fix in 879ba41db1afeb26691c9e05d7cd61142620d7e0 to properly handle linked zoom
states.

google/neuroglancer,google/neuroglancer,google/neuroglancer,janelia-flyem/neuroglancer,google/neuroglancer,google/neuroglancer,janelia-flyem/neuroglancer,google/neuroglancer,google/neuroglancer,janelia-flyem/neuroglancer,janelia-flyem/neuroglancer,janelia-flyem/neuroglancer,google/neuroglancer