Calc parses fractions written using U+2044 FRACTION SLASH

Calc parses fractions written using U+2044 FRACTION SLASH

Fractions of the form 123⁄456 are handled as if written 123:456. Note
in particular the difference in behavior from U+2215 DIVISION SLASH
and U+002F SOLIDUS, which result in division rather than a rational
fraction.
* lisp/calc/calc-aent.el (math-read-replacement-list): Substitute a
colon for any fraction slash.  (Bug#66944)

* test/lisp/calc/calc-tests.el (calc-frac-input): Test various
fraction types.

* etc/NEWS:
* doc/misc/calc.texi (Fractions): Mention fraction slash, precomposed
fractions.

Copyright-paperwork-exempt: yes
(cherry picked from commit 77d9d05df87965409c537f49d59cb5ea632abda1)