R1:7831b9242760

Improve LiskDAO::__call() performance

Summary:
This is kind of expensive and can be significant on, e.g., the
Maniphest task list view. Do a little more caching and some clever nonsense to
improve performance.

Test Plan:
Local cost on Maniphest "all tasks" view for this method dropped from
##82,856us## to ##24,607us## on 9,061 calls.

I wrote some unit test / microbenchmark things:

public function testGetIDCost() {
$u = new PhabricatorUser();
$n = 100000;
while ($n--) {
$u->getID()…