Increase timeout on slow classname search REST API

[wtwhite]

The https://search.maven.org/solrsearch/select endpoint that shadedetector uses to find definitions of a given classname in the Maven central repo can be very slow, even on repeated queries, and this causes timeout errors. I can repro with curl -- I see successful responses that take up to 19s:

C:\Users\walto\Documents\code\shadedetector>curl "https://search.maven.org/solrsearch/select?q=c%3AXmlTypeResolverBuilder&wt=json&rows=200&start=201" > retry_shadedetector_with_curl.out
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100 90112    0 90112    0     0   4522      0 --:--:--  0:00:19 --:--:-- 19770

C:\Users\walto\Documents\code\shadedetector>curl "https://search.maven.org/solrsearch/select?q=c%3AXmlTypeResolverBuilder&wt=json&rows=200&start=201" > retry_shadedetector_with_curl2.out
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100 90112    0 90112    0     0   7505      0 --:--:--  0:00:12 --:--:-- 21153

C:\Users\walto\Documents\code\shadedetector>

(I originally thought the issue was be the networking setup of the Linux VM I'm using, but could repro in the Windows host.)