make OR in journey patterns compile to a valid regular expression
Fix value extracted from negative integers for PostgreSQL.

Fixes: https://github.com/rails/rails/issues/17856.
Merge pull request #17863 from tgxworld/fix_extracated_default_value_for_negative_integers

Fix value extracted from negative integers for PostgreSQL.
tests, use public API to verify default parsing. #17863, #17856
tests, run numeric default tests for every adapter.
Merge pull request #17827 from rkh/rkh-fix-or-pattern

Fix OR in Journey patterns
tests, favor public API over inspecting columns where possible.

This is a follow up to https://github.com/rails/rails/commit/07786c5e75a7b0afdf318063510af6b475e3e04c
and https://github.com/rails/rails/commit/cd2596f55e88fe659592612a793c4f4aa723c9be