Querying with `like` filter throws error if (indexed) field of any child isn't present

[appy-one]

Executing the following query will throw error Cannot read properties of undefined (reading 'toString') if there is an object in the queried collection that does not have a value for the filtered (and indexed) field with like:

const snaps = db.query('users').filter('email', 'like', 'ewout@*').get();

A single user in this collection that has no email field will cause the query to crash