NetworklistlistIO, the update should update the cache

[wjonassen]

Describe the bug
When updating a netlist, removing platform entries and saving does update the database, but it does not update the cache, so if you do a get, you will still get the same old entries. Now, if you add entries in, those will be updated properly, but removing does not.

To Reproduce
Steps to reproduce the behavior:

1. Open a netlist through the API (or web client).
2. Remove platform entries that are already there.
3. Save the netlist (POST) and reload. You will see the removed entries are still there.
4. Now restart the app in tomcat, and you will see that the entries are no longer there.

Expected behavior
Any platform added or removed would be reflected immediately on the subsequent api calls.