fix(NODE-3452): readonly filters not permitted by typings

[nbbeeken]

Under certain usages typescript will disallow readonly arrays, when overriding the results of a find is a notable usage, look to the tests for a more complete list. Additionally the result of find was resulting the in the schema unioned with filter operators, there's a test to confirm that no longer occurs.

[dariakp]

Also, are we addressing the user's find override request?

by the way we should be able to configure the output type since with a filter we can have a different type than the schema type.

or is that addressed with the other projection ticket?

[PaulEndri]

Hi! Me again, hope I'm not bothering. Can you (in the interim, per the above conversation) fix needing to add the as any bit by iterating over the result of Object.entries instead? The following seems to make the transpiler happy:

    Object.entries(indexSpec).forEach(([key, value]) => {
      indexes.push(key + '_' + value);
      fieldHash[key] = value;
    });

[nbbeeken]

Good suggestion! thanks :)