1. Presents the system error message when available,
when applying suggestions

2. Adjusts target branch updates affecting MRs pointing
to it when there are previously created suggestions in
the MR. We just need to compare the HEAD shas from
position and MR source branch.

1. Avoid suggestions being applied on the same file
from reverting previous changes
2. Gracefully use and handle file changes error
when updating the file (though, it does not totally
solves the sync problem for multiple suggestion
applications at once)