In lookup table editing, custom view Modes are not found on server

[Brian Lewis]

When editing a lookup table, a view mode (ie set of column definitions is either created dynamically, or else sourced from the \viewmodes node, using the same context hierarchy as used for views.

Currently this doesn’t work because the path to the viewmodes base folder is incorrectly expressed.

[Brian Lewis]

fix(lookup editing): get custom view mode from server

Resolves #812

→ <<cset 4b99d8dc3ab7>>