When schematic symbols have footprint fields without library name prefixes
(e.g., "DGG56" instead of "Package_SO:DGG56"), the netlist updater's FPID
comparison always fails against the board's fully qualified FPIDs, causing
"Update PCB from Schematic" to perpetually report footprint changes that
can never be resolved.
Match by item name only when the schematic-side FPID has no library
nickname (legacy format), and warn the user to add the library prefix.
Fixes https://gitlab.com/kicad/code/kicad/-/issues/22958
Seth Hillbrand