[PATCH] Fix errhint messages for REPACK (CONCURRENTLY) restrictions

Hi,

The errhint messages added by commit 28d534e2ae0 for REPACK (CONCURRENTLY)
restrictions have two issues:

1. They say "REPACK CONCURRENTLY" without parentheses, inconsistent with
   the actual command syntax and the errmsg text elsewhere in the same file.

2. The TOAST relations hint is missing a trailing period.

The attached patch fixes both issues and also switches to the %s pattern
so translators handle the template without embedding the SQL command name:

  Before:
    HINT:  REPACK CONCURRENTLY is not supported for TOAST relations

  After:
    HINT:  REPACK (CONCURRENTLY) is not supported for TOAST relations.

Thanks,
Baji Shaik
AWS RDS