Clean up search code and unify function returned values
This PR is a cleanup: there is no changes in the search results or in the UI.
Depending if it was "literal search" or not, it was either returning booleans or integers. It's pretty bad so instead it all returns integers.
Another thing I did was to move the add and checks into a `addIntoResults` function to simplify things.
Last thing: I removed a loop in the `sortResults` function and moved its code directly into the first loop.
All these changes are done to make #90630 much smaller.
r? `@jsha`
8bb238b8df