Redirects 18.2

[dorothyyeager]

Summary

What we are after:
In this sprint, we'll need to redirect the old Form 1 letters to the new Form 1 so that users will be able to use the correct form. We'll also add in any other redirects that come up.

Related issues

#5135 - Form 1 letters
#5160 - Partnership page has new URL; will need to update older transition and www redirects.

Completion criteria

• Wagtail redirect entered for old letters for Super PACs and Hybrid PACs redirect to Forms page
• Old proxy redirects updated to for old letters to redirect to new Form 1
• Partnership related redirects are entered for transition and www
• Any other redirects that come up are included in PR
• Testing ticket created

Future work

The testing after release is deployed.