Allow properties with zero values to be included in queries

[frankiejarrett]

We are currently disallowing properties with empty values from being included in the final query array.

This is a problem if you want to query something with an ID of zero, such as a user_id.

We should adjust our definition of what an "empty" property is when building the final query.

Disallowed values

• NULL
• bool(false)
• string(0) "" (an empty string)
• array(0) {} (an empty array)

Allowed values

• string(1) "0"
• int(0)