test(languages): Add test for Polish hyphenated words

According to Polish typography conventions, when a break occurs at
an explicit hyphen, the hyphen gets repeated at the beginning of
the next line.

Co-authored-by: Jakub Kaczor <jakub@jakubkaczor.com>

tests/fix-polish-hyphen.expected

@@ -0,0 +1,23 @@
+Set paper size 	209.7637818	297.6377985
+Begin page
+Mx 	162.4882
+My 	26.9913
+Set font 	Gentium Plus;16;400;;normal;;;LTR
+T	69 76 68 1146 82 16 w=37.7344	(biało-)
+Mx 	10.4882
+My 	46.1913
+T	16 w=5.3906	(-)
+Mx 	15.8788
+T	70 93 72 85 90 82 81 92 w=63.5703	(czerwony)
+Mx 	130.4882
+My 	65.3913
+T	69 76 68 1146 82 16 w=37.7344	(biało-)
+Mx 	168.2226
+T	70 93 72 85 w=27.5078	(czer)
+Mx 	195.7304
+T	16 w=5.3906	(-)
+Mx 	10.4882
+My 	84.5913
+T	90 82 81 92 w=36.0625	(wony)
+End page
+Finish

tests/fix-polish-hyphen.sil

@@ -0,0 +1,13 @@
+\begin[papersize=a7]{document}
+\neverindent
+\nofolios
+\language[main=pl]
+\font[size=16pt]
+
+% Breaks at existing hyphens get a hyphen on the next line
+\kern[width=152pt]biało-czerwony
+
+% Breaks at other places just chill as usual
+\kern[width=120pt]biało-czerwony
+
+\end{document}