preserve default value of invalid autoincrement column types in Postgres (DAT-8670)

[StevenMassaro]

Postgres reports that varchar columns are autoincrement and have a default value when created like this:

CREATE SEQUENCE mysequence INCREMENT 5 START 100;
CREATE TABLE products ( product_no varchar(20) DEFAULT nextval('mysequence'));

and this change allows Liquibase to snapshot these columns properly. The default value is preserved, and the autoincrement information is removed.

[github-actions]

Unit Test Results

  4 125 files  +11    4 125 suites  +11   38m 1s ⏱️ + 1m 57s
  4 340 tests +  1    4 126 ✔️ ±  0     214 💤 +  1  0 ❌ ±0 
47 080 runs  +11  42 448 ✔️ ±  0  4 632 💤 +11  0 ❌ ±0 

Results for commit 6cef945. ± Comparison against base commit a8440e1.

♻️ This comment has been updated with latest results.