Distinction between already existing files / added files / modified files + add a way to filter them by modification before alphabetical order

[FirstMegaGame4]

Might be interesting to add the modification filter activator at the right of the filter input.

[craftyneil]

you can do

the_vector_with_all_the_files_sorted = the_vector_with_all_the_files.sort_by(
        |a, b| a.to_lowercase().cmp(&b.to_lowercase())
);

or

the_vector_with_all_the_files_sorted = the_vector_with_all_the_files.sort_by_key(
        |name| name.to_lowercase()
);

and put all the files in a list and then filter when it was modified, added or others things and put the filtered item into another list or a sublist to separate the files

[FirstMegaGame4]

these aren't managed through vectors
Illusionna is using a kind'of virtual filesystem (that I will probably externalise in the future) allowing to convert received path from apis into an complex tree structure with data, which allows to display content in a clean way
I have already most of the code in need to close the issue, I'm simply testing multiple design that would correctly fit Illusionna's UI