localedata: bn_BD, bn_IN: use full Gregorian month names for abmon

Bangla has no conventional abbreviated form for month names. The
existing abmon entries only truncated January and February ("জানু",
"ফেব"), while March through December were already spelled out in
full -- an inconsistent and non-standard %b output that native
speakers do not recognize as valid abbreviations. "জানু" is also an
unrelated, existing Bengali word meaning "knee".

Use the full month name for abmon as well as mon in both bn_BD and
bn_IN, matching the informal convention already used for the other
ten months and consistent with CLDR's bn Gregorian calendar data,
which likewise leaves several months unabbreviated for the same
reason (see CLDR-19739, filed separately for the CLDR side of this:
https://unicode-org.atlassian.net/browse/CLDR-19739).

Signed-off-by: Azharul Haque <haque@azharul.com>
Reviewed-by: Mike FABIAN <mfabian@redhat.com>

localedata/locales/bn_BD

@@ -107,9 +107,10 @@ day         "রবিবার";/
             "শুক্রবার";/
             "শনিবার"
 
-%janu febru march apri may jun jul aug septe octo nove dece
-abmon       "জানু";/
-            "ফেব";/
+% Bangla has no established convention for abbreviating month names,
+% so the abbreviated (%b) and full (%B) forms are the same.
+abmon       "জানুয়ারী";/
+            "ফেব্রুয়ারী";/
             "মার্চ";/
             "এপ্রিল";/
             "মে";/

localedata/locales/bn_IN

@@ -89,8 +89,10 @@ day         "রবিবার";"সোমবার";/
 
 %
 % Abbreviated month names (%b)
-abmon       "জানু";/
-            "ফেব";/
+% Bangla has no established convention for abbreviating month names,
+% so the abbreviated (%b) and full (%B) forms are the same.
+abmon       "জানুয়ারী";/
+            "ফেব্রুয়ারী";/
             "মার্চ";"এপ্রিল";/
             "মে";"জুন";/
             "জুলাই";"আগস্ট";/