Convert partial dump to a different marker or a zero-filled full dump

[vladko312]

Some cards have unknown keys for some sectors, while others have Access Conditions like 0870FF preventing access to some blocks. In this case, MCT marks these blocks with dashes. It would be a good idea to add a way to quickly replace them wis question marks (flipper zero marks them in this way) or zeroes (as proxmark3 does). It would be useful for comparing dumps across platforms, as well as for exporting partial dumps in binary format.