Warnings when a level is deleted but had approval settings or status for user

[kimcoleman]

Describe the bug
If a membership level gets deleted, there is a warning shown on the Membership Account page. We should resolve this warning and also look to move these status notices into the relevant card for that level in the "My Memberships" section of the account page with PMPro v3.1+

I am also getting this issue on activation intermittently: Deprecated: Automatic conversion of false to array is deprecated in /Users/kimberlycoleman/Local Sites/pmprokimfork/app/public/wp-content/plugins/pmpro-approvals/pmpro-approvals.php on line 1752

To Reproduce
Steps to reproduce the behavior:

1. Check out for a level that requires approval.
2. As admin, delete that level
3. Return to Membership Account page for the user that needed approval.

It may also be affecting the protected content messages - not 100% sure on that.

Expected behavior
Skip deleted levels.

[ipokkel]

Another occurrence of this issue was reported. #605347