[1.7.x] Fixed #22720 -- Migrations attempt to create _order twice.

Backport of 6cfa2fae39 from master
[1.7.x] Adding test to fix of duplicate _order fields (#22720)

Backport of bf9953cfb8 from master
[1.7.x] Simplified, very slightly, some code in the oracle backend

Backport of e79725cdf9 from master
[1.7.x] Fixed several typos in Django

Backport of 1dcc603eff from master
[1.7.x] Fixed a typo that Tim Graham noticed

Backport of d240b29c08 from master
[1.7.x] Removed unused import.
[1.7.x] Making SQL management commands migration aware.
[1.7.x] Fix test failure caused by 3149cdce32e7261b2d44128ab712c4d4f1a5d429
[1.7.x] Fixed #22682 -- `makemigrations` will create `MIGRATION_MODULES` package

`makemigrations` will automatically create the package specified
in `MIGRATION_MODULES` if it doesn't already exist.

Thanks ovidiuc4 for the report.
[1.7.x] Improved deprecation plan links in release notes.

Backport of 7ff326928a08d4c51141768bd305a44ca5ecb2e7 from master
[1.7.x] Fix additional test failures caused by migration pollution