databases/postgresql??-*: Upgrade to latest version

PostgreSQL 13.3, 12.7, 11.12, 10.17, and 9.6.22 Released!

The PostgreSQL Global Development Group has released an update to all supported
versions of our database system, including 13.3, 12.7, 11.12, 10.17, and
9.6.22. This release closes three security vulnerabilities and fixes over 45
bugs reported over the last three months.

Security fixes in this release:

CVE-2021-32027: Buffer overrun from integer overflow in array subscripting

calculations

CVE-2021-32028: Memory disclosure in INSERT ... ON CONFLICT ... DO UPDATE

CVE-2021-32029: Memory disclosure in partitioned-table UPDATE ... RETURNING

Also plenty of bug fixes. See the release note for details.

Changes to the port:

Make sure we use the matching version of llvm. This fixes a problem with the
llvm version string not being monotonically increasing with the version
number. [1]

Better pkg message about checksums for postgresql 12+. [2] [4]

Adjust login class parameter to adhere to the documentation in rc.subr(8) [3]:

The rc.conf parameter for the login class of the postgresql daemon has
changed name from postgresql_class to postgresql_login_class, since
rc.subr(8) states that the parameter should be named ${name}_login_class.

Allow parallel builds. [5]

Correct the directory name for the user postgres in pkg message. [6]

PR: 250824 [1], 253558 [2], 236060 [3], 233106 [4], 230656 [5]
PR: 226674 [6]
Submitted by: Michael Zhilin [2], Michael Zhilin [3], Dmitry Chestnykh [4]
Submitted by: Steve Wills [5], knezour [6]

Security: 76e0bb86-b4cb-11eb-b9c9-6cc21735f730
Security: 62da9702-b4cc-11eb-b9c9-6cc21735f730

Release notes: https://www.postgresql.org/docs/release/