This adds the ability to export the pin table content to a CSV file
or the clipboard as CSV, then re-import it from CSV or TSV. This allows:
* to round-trip pin table data via a spreadsheet program, so that the pin
data can be manipulated in a richer/more familiar editing environment
* an import method to bring in tabular pin data from other formats
"semi-automatically", without having to write a full-blown symbol generator.
Relates-To: https://gitlab.com/kicad/code/kicad/-/issues/19207
