public static unowned string** search (string search_string)
Searches desktop files for ones that match
The return value is an array of strvs. Each strv contains a list of applications that matched
search_string with an equal score.
The outer list is sorted by score so that the first strv contains the best-matching applications, and so on. The algorithm for determining
matches is undefined and may change at any time.
None of the search results are subjected to the normal validation checks performed by DesktopAppInfo (for example, checking that the executable referenced by a result exists), and so it is possible for DesktopAppInfo to return null when passed an app ID returned by this function. It is expected that calling code will do this when subsequently creating a DesktopAppInfo for each result.
the search string to use