feat(eas): Add SOGoEASDisableUI system parameter to remove EAS options in UI when ActiveSync is not used

SoObjects/SOGo/SOGoSystemDefaults.h

@@ -121,8 +121,9 @@ static const NSString *kDisableSharingCalendar = @"Calendar";
 - (int) maximumSyncResponseSize;
 - (int) maximumPictureSize;
 - (BOOL) easSearchInBody;
+- (BOOL) isEasUIDisabled;
 
-- (BOOL) isPasswordRecoveryEnabled;
+- (BOOL)isPasswordRecoveryEnabled;
 - (NSArray *) passwordRecoveryDomains;
 - (NSString *) JWTSecret;
 

SoObjects/SOGo/SOGoSystemDefaults.m

@@ -746,6 +746,11 @@ _injectConfigurationFromFile (NSMutableDictionary *defaultsDict,
   return [self boolForKey: @"SOGoEASSearchInBody"];
 }
 
+- (BOOL) isEasUIDisabled
+{
+  return [self boolForKey: @"SOGoEASDisableUI"];
+}
+
 //
 // See https://msdn.microsoft.com/en-us/library/gg672032(v=exchg.80).aspx
 //