pgsql: Use format_type_be() instead of TypeNameToString() for some more

Log Message:
-----------
Use format_type_be() instead of TypeNameToString() for some more user-facing
error messages where the type existence is established.

Modified Files:
--------------
    pgsql/src/backend/commands:
        comment.c (r1.103 -> r1.104)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/comment.c?r1=1.103&r2=1.104)
        functioncmds.c (r1.98 -> r1.99)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/functioncmds.c?r1=1.98&r2=1.99)
        tablecmds.c (r1.267 -> r1.268)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/tablecmds.c?r1=1.267&r2=1.268)
        typecmds.c (r1.124 -> r1.125)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/typecmds.c?r1=1.124&r2=1.125)
    pgsql/src/test/regress/expected:
        alter_table.out (r1.110 -> r1.111)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/expected/alter_table.out?r1=1.110&r2=1.111)