web: Fix urls with spaces and other invalid characters

To avoid the problem of urls with spaces and weird characters (like
"/api/tlbr/avail_hist/SUL/PR/LAGOA D'ANTA"), use id_city and id_point
instead of city and telecenter names. Now queries return an "id", which
is used to build the urls, and a "cat" representing the full name to be
displayed.

Signed-off-by: Eduardo L. Buratti <elb09@c3sl.ufpr.br>