Make webservice plugin usable in security aware companies/customers.

In last version of webservice plugin can call listObjects and getObject only admin user. This makes this plugin useless for security aware company.

For example. If I want to integrate GLPI for example with ansible I can do it using glpi_ansible (https://github.com/Webelys/glpi_ansible) This ansible plugin calls listObjects and getObject and stores credentials in text file. Due to limitation of web service plugin I have to create service account in GLPI with administrator privileges. When servers administrators which are using ansible are not GLPI administrators, the they will got credentials for administrators access to GLPI and this is BAD.

Allow use listObjects and getObject for non admin user and control access to object types according standard GLPI rights.