vcs: Refactor "SingleChangeListCommitWorkflowHandler" - remove explicit dependency on "CommitChangeListDialog"

This breaks some plugins that explicitly cast "CheckinProjectPanel" to "CommitChangeListDialog". But such plugins should be updated anyway to support non-modal commit.

cba92fe6862903d82ce0df11e504defaaba7678a follow-up

vcs: Refactor commit dialog - move logic calling "CheckinHandler.includedChangesChanged()" to workflow handler

Alien logic is not affected - "inclusion event" is currently not fired in "AlienChangeListBrowser" as it doesn't show checkboxes. And if checkboxes will be enabled in alien commit, "CheckinHandler.includedChangesChanged()" should also be called.

30ef642a follow-up