[Rachana] Add glyph for യ്വ y1v1

Signed-off-by: Rajeesh K Nambiar <rajeeshknambiar@gmail.com>
[Meera] Add missing mlm2 akhn rule for യ്വ y1v1 glyph

Signed-off-by: Rajeesh K Nambiar <rajeeshknambiar@gmail.com>