[1.7.x] Fixed #23581 -- Prevented extraneous DROP DEFAULT statements.

Thanks john_scott for the report and Markus Holtermann for review.

Backport of ab4f709da4516672b0bd811f2b4d0c4ba9f5b636 from master
[1.7.x] Added test for an intermediate swappable model change in migration state.

refs #22563

Backport of fca866763acb6b3414c20ca3772b94cb5d111733 from master
[1.7.x] Revert "Updated some docs for the delayed deprecation of legacy table creation; refs #22340."

The deprecation was moved back to 1.9 in
61da5f3f02f34810aaa6fcddac3808318a5b95c4.

Backport of d7fc6eb8ca67a6a628e8c7ce669731cf563606e7 from master