Speed up ContactResolver by removing looping

The previous contactresolver was O(E*A) where E was the number of commhistory events and A was the number of addresses in the contacts db. (Technically something like O(E*A*n) where n is the average number of addresses per contact, but n is usually a small number)

I rewrote its core loop so that it canonicalizes the addresses, which allows hashtable lookups instead of list scans. From the commit message:

- Canonicalize requested addresses so that they can be looked up in hashes (using a canonicalization that matches what addressMatchesList used to do)

- Fill in all the resolved contacts when the events list is sent out, instead of looping over all the events whenever something changes.

- Side effect: having lots of duplicate addresses in the events list no longer slows down contactUpdated processing

The benefit is visible in voicecall-ui startup, which in tests on iamer's phone showed improvement from 40s of cpu time to 12s of cpu time. He has about 8000 commhistory events and about 500 contacts.
I wonder if it would make any difference to do:

    const QLatin1String prefix(...);
    return localUid.length() > prefix.length() && localuid.startsWith(prefix);