Support querying groups by name and name part

This adds two query operators for group queries:

1. name:
   Exact match on the group name (case-insensitive)
2. inname:
   Prefix match on a group name part (case-insensitive)

Change-Id: Iedec2574690881470ba7f0ff7cd12263e466352f
Signed-off-by: Edwin Kempin <ekempin@google.com>

Documentation/rest-api-groups.txt

@@ -226,7 +226,7 @@ As result a list of link:#group-info[GroupInfo] entities is returned.
 
 .Request
 ----
-  GET /groups/?query2=uuid:59b92f35489e62c80d1ab1bf0c2d17843038df8b HTTP/1.0
+  GET /groups/?query2=inname:test HTTP/1.0
 ----
 
 .Response
@@ -238,13 +238,22 @@ As result a list of link:#group-info[GroupInfo] entities is returned.
   )]}'
   [
     {
-      "url": "#/admin/groups/uuid-59b92f35489e62c80d1ab1bf0c2d17843038df8b",
+      "url": "#/admin/groups/uuid-68236a40ca78de8be630312d8ba50250bc5638ae",
       "options": {},
-      "description": "Gerrit Site Administrators",
-      "group_id": 1,
-      "owner": "Administrators",
+      "description": "Group for running tests on MyProject",
+      "group_id": 20,
+      "owner": "MyProject-Test-Group",
       "owner_id": "59b92f35489e62c80d1ab1bf0c2d17843038df8b",
-      "id": "59b92f35489e62c80d1ab1bf0c2d17843038df8b"
+      "id": "68236a40ca78de8be630312d8ba50250bc5638ae"
+    },
+    {
+      "url": "#/admin/groups/uuid-99a534526313324a2667025c3f4e089199b736aa",
+      "options": {},
+      "description": "Testers for ProjectX",
+      "group_id": 17,
+      "owner": "ProjectX-Testers",
+      "owner_id": "59b92f35489e62c80d1ab1bf0c2d17843038df8b",
+      "id": "99a534526313324a2667025c3f4e089199b736aa"
     }
   ]
 ----

Documentation/user-search-groups.txt

@@ -10,6 +10,17 @@ Operators act as restrictions on the search. As more operators
 are added to the same query string, they further restrict the
 returned results.
 
+[[inname]]
+inname:'NAMEPART'::
++
+Matches groups that have a name part that starts with 'NAMEPART'
+(case-insensitive).
+
+[[name]]
+name:'NAME'::
++
+Matches groups that have the name 'NAME' (case-insensitive).
+
 [[uuid]]
 uuid:'UUID'::
 +