CsvTagImporter / CsvTagExporter parse and emit Kepware-format AB CIP tag
CSVs (Tag Name, Address, Data Type, Respect Data Type, Client Access,
Scan Rate, Description, Scaling). Import maps Tag Name → AbCipTagDefinition.Name,
Address → TagPath, Data Type → DataType, Description → Description,
Client Access → Writable. Skips blank rows + ;/# section markers; honours
column reordering via header lookup; RFC-4180-ish quoting.
CsvImports collection on AbCipDriverOptions mirrors L5kImports/L5xImports
and is consumed by InitializeAsync (declared > L5K > L5X > CSV precedence).
CLI tag-export command dumps the merged tag table from a driver-options JSON
to a Kepware CSV — runs the same import-merge precedence the driver uses but
without contacting any PLC.
Tests cover R/W mapping, blank-row skip, quoted comma, escaped quote, name
prefix, unknown-type fall-through, header reordering, and a load → export →
reparse round-trip.
Closes#232
