Simplified plugin interfaces (#1745)

* Simplified plugin interface

* Allow not implemented

* Fixes

* Fixed CPU plugin tests

* Fixed tests dependencies

* Fixes

* Fixed GPU plugin compilation

* Renamed plugin

* Fixes

* Removed tests for plugin base

* Fix2

* Fix 2

* Define a macro to define plugin creation function

* Clean-up

* Fixed OSX build

* Fixed CentOS

* Fixed exception catch / throw

* Fixed clang issue

* Fixed python tests on macOsx

docs/template_plugin/src/template_plugin.cpp

@@ -6,7 +6,6 @@
 #include <ie_plugin_config.hpp>
 
 #include <hetero/hetero_plugin_config.hpp>
-#include <cpp_interfaces/base/ie_plugin_base.hpp>
 #include <threading/ie_executor_manager.hpp>
 
 #include <ngraph/op/util/op_types.hpp>