fix: changes being lost when switching files
fix: changes being lost when switching files

File that was not saved should warn to be saved before changing to another
directory or file.

Signed-off-by: Bruno Bottazzini <c92d71c55f49bd220e26b4af231350d119acce9e@intel.com>

solettaproject/soletta-dev-app,brunobottazzini/soletta-dev-app,solettaproject/soletta-dev-app,brunobottazzini/soletta-dev-app,brunobottazzini/soletta-dev-app,solettaproject/soletta-dev-app