Unable to clear shared profile country value

[brettski]

Describe the bug
Once a value is set for Country in a shared profile, this value does not clear. Even after clearing the value and saving the value still remains in the data store.

When the value is cleared in the form it is set to undefined, I am thinking it needs to be either empty string or null to clear correctly.

This could be corrected on the api as well if the update method is refactored for the shared profile. Currently an update merges data so if the data isn't in the update object that value remains in the document.
I believe both sites send all data it wants in the record, so this may be the correct action to take

To Reproduce
Steps to reproduce the behavior:

1. Go to /my/profiles/shared
2. Ensure you have a profile record saved in the database with a country value
3. Click on clear the country field value
4. Save the record
5. Refresh the page
6. Notice that the country value comes bace

Expected behavior
The country value should not be retained