Two entries in test library.xml used to point to the same file path.
Note that though the third entry pointed to a different file name
it is a symbolic link to the same file.
Now all three entries point to pseudo-different files (having the
same content behind them).
This change is needed so that tests don't break when detection of
conflicting book names is made stricter.
Presence of the "faviconMimeType" attribute in a book entry in library.xml
file is enough for libkiwix to assume that the book contains an illustration
(even if the "favicon" attribute is missing).
The HumanReadableId can contains special char (`&`/`=`/...)
As it is used as to create a url in the opds template,
we must url encode it.
- We don't need to encode the book id as it is a uuid, it never contains
special char.
- We don't need to encode the book url as it is read from the library and
the url must already be correctly encoded in the library.xml.
(tests modified accordingly)