cel, cdr: Assigned separator for column name and values.

Use a separator string between column names and values for SQL sentences
instead of evaluating the separator to use each time.

This change adds a space after the comma in constructing SQL sentences.
Before the SQL was created like "INSERT INTO cdr(calldate,clid,dst"
without spaces between column name and values.

The files applied this change are cdr/cdr_adaptive_odbc.c, cdr/cdr_pgsql.c,
cel/cel_odbc.c

ASTERISK-25109 #close
Reported By: Rodrigo Ramírez Norambuena <decipher.hk@gmail.com>

Change-Id: Ia5a1a161f5e26e1643703b30f8cc9cf0860cc7ea