Note: This commit somewhat relaxes validation of non variable
`<updated>` elements in the OPDS feed - the contents of any `<updated>`
element is replaced with the YYYY-MM-DDThh:mm:ssZ placeholder.
Each sugestions used to be stored as vector of strings to hold various values
such as title, path etc inside them. With this commit, we use the new
dedicated class `SuggestionItem` to do the same.
With openzim/libzim#545 we now support snippet generation of titles
which can be used as the display label on the ui for highlighted titles
via the "label" field.
The old version used plain title which is still available in the value
field.
Returning status code 204 in case of an empty results doesn't show the
empty results page as described in #466. Reverting the changes in #396
fixes the issue.
Android clang complains about the fact it cannot move the
`std::unique_ptr<ContentResponse>` into a `std::unique_ptr<Response>&&`
(for the implicit `std::unique_ptr<Response>` constructor).
Let's help him a bit.
This is only an "interface" for now as other type of response (entry) may
be "transformed" to a ContentResponse.
We cannot move all the code in the class.