add ‘htaglib’ package

HTagLib is binding to C API of popular C++ library for reading and
editing of audio meta information (i.e. tags) of many popular audio
formats. There are at least two other projects doing “the same” thing,
both are almost identical and very low-level.

This project provides high-level Haskellish interface (e.g. it uses
applicative interface to read tags directly into your data structure,
etc.). Reading and writing of meta data is performed as “atomic”
operations, so it's impossible to forget to close file, etc. It's also
type-safe.

build-constraints.yaml

@@ -1505,6 +1505,7 @@ packages:
 
     "Mark Karpov <markkarpov@opmbx.org> @mrkkrp":
         - megaparsec
+        - htaglib
 
     "Thomas Bereknyei <tomberek@gmail.com>":
         - multiplate