A sheetpath is required to correctly resolve text variables.
Depending on currentSheet is rife with bugs.
There are many places where we do *not* want to be prepending
field names to the field values, such as netlisting,
building PDF hypertext menus, etc.
Also, Find/Replace needs to work on unresolved text, as
that's what we're going to display (and if replace nuked
your variable references you wouldn't be happy).
(cherry picked from commit b41d446f58)
Some of these are due to moving to wxWidgets 3.2, but I'm not sure
all of them are. In particular, the need for CallAfter() in the
search pane's selection handler is probably just a wxWidgets bug on
Mac (the control lies about the current selection inside the event
handler).
Also sets better column widths in the search pane.