Before and after review visitors refactoring

Change-Id: I374b4749ab0ba653bc11ea34d6de416d20ad1f3c
StaticScore and SummaryMessage visitors

Change-Id: I90830e55b6a9b3e163760f6b0029de9adb438488
Update Stash facade to new API

Change-Id: I35796c6aaef3e60038f8757a30710db4bccedcc4
Fix Stash facade tests

Change-Id: Ia14819bb53b47c663c5d97305baa4a8c949dfc94
Extract ReviewInputBuilder

Change-Id: Id7e010666794b98fba68a231070108d5aa393de4
Fix tests

Change-Id: I6af7165e5a842669288186db7c3cc3cb864bfc6f
Extract ProcessorBuilder for Engine

Change-Id: Ia50928fd0235ed4eaafa0770d126a9fb9f8d4151
Move visitors package to engine

Change-Id: Iaea6f002b518f10d97d5127d72668cd238dd62f4
Move Connectors enum to connector package

Change-Id: I6b7bc98d7a277fc6b02a51afe6da5dbe5906da89
VisitorBuilder and tests

Change-Id: I2bf15012e6c38c6d2ea66ee2f316634495c677e3