[feat] plugin Self Information: improve keyword matching

This change does the following things:

- the `ip` keyword is now case-insensitive
- if the query includes `my ip` it will now also match

In order to avoid too many false matches, the `ip` keyword alone matches only if
it's the _only_ word, but the inclusion of `my` loosens that to be inclusive of
users type a phrase (eg, "what is my ip", "tell me my ip", "my IP address",
etc).

Better answer context

Previously this plugin simply dumped your IP or user-agent string as an answer.
This tiny change just adds some text to contextualize those answers (eg, "Your
IP is: 1.2.3.4" instead of just "1.2.3.4").

searx/plugins/self_info.py

@@ -13,17 +13,20 @@
 query_keywords = ['user-agent']
 query_examples = ''
 
+# "ip" or "my ip" regex
+ip_regex = re.compile('^ip$|my ip', re.IGNORECASE)
+
 # Self User Agent regex
-p = re.compile('.*user[ -]agent.*', re.IGNORECASE)
+ua_regex = re.compile('.*user[ -]agent.*', re.IGNORECASE)
 
 
 def post_search(request, search):
     if search.search_query.pageno > 1:
         return True
-    if search.search_query.query == 'ip':
+    if ip_regex.search(search.search_query.query):
         ip = get_real_ip(request)
-        search.result_container.answers['ip'] = {'answer': ip}
-    elif p.match(search.search_query.query):
+        search.result_container.answers['ip'] = {'answer': gettext('Your IP is: ') + ip}
+    elif ua_regex.match(search.search_query.query):
         ua = request.user_agent
-        search.result_container.answers['user-agent'] = {'answer': ua}
+        search.result_container.answers['user-agent'] = {'answer': gettext('Your user-agent is: ') + ua}
     return True