Add 404 when namespace not found

[zipofar]

When we find, update, delete namespace we sent error to sentry if namespace not found. For avoid this we should extract 404

E.g. error

HOW TO TEST:

1. Try to create deployment Expected: all should be good

2. Try to update deployment Expected: all should be good

3. Try to delete deployment Expected: all should be good

[fedorov-dualboot]

tested. OK

• create deployment

Actual: all should be good

• update deployment

Actual: all should be good

• delete deployment

Actual: all should be good. no errors in sentry.

https://www.loom.com/share/0201a21c990b4bdea196c86a526041aa

[fedorov-dualboot]

verified on prod. OK Actual: all should be good. no errors in sentry.