[INSTALLER] Add a more informative summary on the results of the update of the existing codebase

[AlexSkrypnyk]

Currently this says:

 ┌──────────────────────────────────────────────────────────┐
 │ Finished updating Vortex                                 │
 │ ────────────────────────                                 │
 │                                                          │
 │ Please review the changes and commit the required files. │
 └──────────────────────────────────────────────────────────┘

But we also can say how many files need to be resolved etc.