Cannot add new entry to multi-valued attribute using a path filter

[barryhagan]

Describe the bug

Similar to the issue in #42, when using Azure AD, SCIM PATCH requests can be sent using filters to add entries to a multi-valued attribute. The fix for #42 handles completely missing or empty array attributes, but we also need to support adding a new value to an existing non-empty array.

Attempting this type of PATCH currently throws with this message: Invalid SCIM Patch: Target location is a multi-valued attribute for which a value selection filter (:patch.value) has been supplied and no record match was made.

Additionally, when throwing NoTarget, the message should include the patch.path, not the patch.value. Right now you get the value you are trying to set, not the filter path.

To Reproduce

• Create a SCIM user that has a "home" address.
• Attempt to PATCH that user with a new "work" address.

{
    "schemas": [
        "urn:ietf:params:scim:api:messages:2.0:PatchOp"
    ],
    "Operations":
    [
        {"op":"Add", "path":"addresses[type eq \"work\"].formatted", "value":"123 fake st."}
    ]   
}

Expected behavior
The new work address is added, and the user now has both "home" and "work" type addresses.

Additional context
Add any other context about the problem here.