Git: Introduce Recover Deleted Files action

Change-Id: I913c07522a8ca82366fd142597430c02e53faa27
Reviewed-by: André Hartmann <aha_1980@gmx.de>
Reviewed-by: Tobias Hunger <tobias.hunger@qt.io>

src/plugins/git/gitplugin.h

@@ -112,6 +112,7 @@ private:
     void logRepository();
     void undoFileChanges(bool revertStaging);
     void resetRepository();
+    void recoverDeletedFiles();
     void startRebase();
     void startChangeRelatedAction(const Core::Id &id);
     void stageFile();