Add an HC reload API to DomainLifecycleUtil

DomainLifecycleUtil includes a number of methods that when combined are the right way to do an HC reload in tests. Effect is we have a number of spots in the domain testsuite where these are being combined. Task here is to work out a useful overall method that can handle the bulk of these cases in 1 go.

Methods are:

executeAwaitConnectionClosed
awaitHostController
awaitServers

A vague thought is to add a "reload" method with a few params that can configure the reload op (admin-only, restart-servers) and determine whether and how long the method should wait for HC reload and whether and how the method should wait for server reload. Use Boolean and Long for params instead of primitives, with null meaning ignore that bit.

See the ServerReload class which has similar utils for standalone servers.