Stream result deserialization

[Iizuki]

Is your feature request related to a problem? Please describe.

Currently the search result Streams return Records which you still have to deserialize into user types by calling Record::to_record.

Something along these lines is always needed:

let deserialized_stream = ldap_stream.map(|record| {
    record.and_then(Record::to_record)
});

Describe the solution you'd like

It would be more ergonomic for the user if the deserialization happened inside the library. The lines above wouldn't have to be used.

Implementation

It should be fairly simple. Just adding the code above to the streaming search functions would do most of the work. Or perhaps it would be more efficient to just do it manually inside the unfold right at the source.

A type parameter for the target type would have to be added though. There might be some nuance here.

I might send a PR eventually myself, but it's probably going to be a while till I have time.