Expose a method to escape reference prefixes

[borgar]

There is a reasonable case (such as while looping through a JSON spreadsheet structure) where you are holding a sheetname and a cell ID and want to construct a full reference. It would be nice to have access to stringifyPrefix to be able to:

const fullID = stringifyPrefix([ sheetName ]) + cellID;

Rather than having to go through the process of parsing everything:

const fullID = stringifyA1Ref({ ...parseA1Ref(cellID), context: [ sheetName ] });