Add search and read RPC access to ir.calendar*

Those access are needed by the client to display the selection widget related
to those models. They do not have it by default because they do not inherit
from ModelView.

issue7996

trytond/ir/calendar_.py

@@ -3,6 +3,7 @@
 
 from ..cache import Cache
 from ..model import ModelSQL, fields, Unique
+from ..rpc import RPC
 from ..transaction import Transaction
 
 
@@ -15,6 +16,12 @@ class _Calendar(ModelSQL):
     def __setup__(cls):
         super().__setup__()
         t = cls.__table__()
+        cls.__rpc__.update({
+                'read': RPC(),
+                'search': RPC(),
+                'search_count': RPC(),
+                'search_read': RPC(),
+                })
         cls.index.domain = [
             ('index', '>=', cls._min_index),
             ('index', '<=', cls._max_index),