Improve in-mem typeahead performance

[junaidzm13]

We're currently sorting all table rows only to get 10 distinct values in the end on every typeahead RPC call. Which turns out to be a bottleneck if we have a large table. Local tests have shown that it takes around 1 second for the method to return 10 distinct values for a table with 1 million rows.

It might be better if we can instead return the first 10 distinct values that match the given criteria / filters and not care about sorting (since we're returning only 10 values, sorted / unsorted wouldn't make much of a diff in terms of UX since the user doesn't have the scroll functionality anyways).