add PGProperty fields (conditionally) to reflection config

[bobisageek]

fixes #1046

The pg driver appears to use reflection to check annotations on fields. This change will make those fields available.

The executable sizes produced by my build process are a) not in the "reference context" for size and b) not amazingly consistent, but as far as I can tell:

• when postgres flag is false, the executable size with the change is about 1KB larger than without the change
• when postgres flag is true, the executable seems to consistently be smaller by 100KB - 1MB with the change than it is without the change (I don't understand that, but it seems to work out that way on Windows)

Regarding functional testing, I was able to use the postgresql-test class with BABASHKA_TEST_ENV=native (with removing the tu/jvm? condition) in

babashka/test/babashka/postgresql_test.clj

Line 21 in 2bb7499

(if (and tu/jvm? (jdbc-feature-flag?) (pg-feature-flag?))

pre-change, this test exhibits a similar behavior to that described in #1046 (throwing a java.lang.ExceptionInInitializerError). Post-change, the test passes. I also tested using a postgres container to more directly reproduce the issue described and verify that the issue is resolved by the change.

[borkdude]

Thanks!