Make INFO messages consistent in various index *validate() functions

Hi,

While experimenting with operator class support functions I saw following
INFO message generated by nbtvalidate():

btree operator family "bpchar_ops" contains function
bpcharcmp(character,character) with wrong signature for support number 1
The 'support number 1' above looks somewhat raw. Some of the other INFO
messages in other index validate function(ginvalidate, gistvalidate) use
the term "support procedure" or "support function".

gin operator class \"%s\" is missing support function %d
This message seems to use friendlier term. In fact the number is actually
for a Support Procedure.

Probably the first message above, when restructured as shown below, might
be more friendlier:

btree operator family "bpchar_ops" contains function
bpcharcmp(character,character) as support procedure 1, with wrong signature
Would it be worth an effort to make these messages consistent and more user
friendly.

Regards,
Neha