Stop using deprecated libkiwix methods

[kelson42]

libkiwix 10.x.y have deprecated many methods and function which I guess are still in used in Kiwix iOS and macOS. This has two consequences:

• Many warning at Kiwix compilation time
• Stop us to removed these old/deprecated primitives in future libkiwix releases.

Would be beneficial to remove the usage of these deprecated methods and use modern/new API of libkiwix.

The effort has already been made in Kiwix Tools, see kiwix/kiwix-tools#535 and this PR might help to know what to do with Kiwix For iOS and macOS.

[automactic]

Are the classes mentioned in kiwix/libkiwix#430 all that needs to be updated? If it is all, then I have already finished migrating to the new classes

[kelson42]

@automactic The list is not complete IMO, just make a compilation run and see if you have deprecation warnings. If not, then this is Ok.

[automactic]

There are no deprecation warnings right now. Looks like I can close this