They are not used at all and the windows version need some extra libs
that complexify the code.
Remove them for now. If it happens that they are needed, we will readd
them.
The `common` name is from the time where kiwix was only one repository
for all the project (android, desktop, server...).
Now we have split the repositories and kiwix-lib is the "common" repo,
the "common" directory is somehow nonsense.
