Remove Inbox module and references

[mattbell87]

Delete the inbox module

• Remove module
• Remove notification type
• Migrations

[mattbell87]

Playwright tests seem to pass in CI, but several fail codespaces through vscode or in the terminal, mostly timeout related I think (the 5000ms).

[adam-buckley]

Looking good so far!

[mattbell87]

Hey @adam-buckley I may need some help with the migration. Its not a complicated migration, but I've tried a couple of things and php cmfive.php install migrations doesn't remove an inbox table if it exists.

I've tried these but I think I may be off the path a bit:

• Adding an SQL file to the install/updates directory. Is this dir still used?
• Adding a migration PHP file to the admin module migrations. Also is this the correct place to put a migration for the inbox module, or is there a more generic place?

Cheers