Add format strings to select command

[nwagner84]

This PR adds the possibility of using PICA format strings in a select expression.

Examples

$ pica print aa.dat | grep '029A'
029A $a Deutschland $g Bundesrepublik $b Auswärtiges Amt $b Bibliothek

$ pica select '[email protected],029A{ a <$> (" (" g ")" <*> " / " [xb] <*> ", " n)}' aa.dat
004914848,Deutschland (Bundesrepublik) / Auswärtiges Amt / Bibliothek

$ pica select '[email protected],028[A@]{ [aP] <$> (", " d <*> " " c) | !U? || U == "Latn" }' goethe.dat
118540238,"Goethe, Johann Wolfgang"
118540238,"Goethe, Johan Wolfgang von"
118540238,"Goethe, Johan Wolphgang"
118540238,"Goethe, Johan W. von"
118540238,"Goethe, Joh. Wolfg. v."
...

Notes

• Parsing of a Path expression takes precedence over a Format expressions. For example, 028A{ [ag] } is a valid Path and Format expression, but interpreted as Path. This expression can be turned into a Format expression by using a quantifier 028A{ [ag].. } or 028A{ [ag]..1 }.