[Plugins test] Add func tests for import/export support by plugins (#4847)

* [Plugins test] Add functional test for correct import/export support by plugins

Test suite creates number of models with various precisions.
For each model:
- If plugin doesn't support IMPORT_EXPORT_SUPPORT metric - skip the test
- Try LoadNetwork without cache enabled fails - skip the test
- Do one inference
If Load and Infer request is succeeded and plugin has import metric:
- Load network with cache enabled. Infer request and compare outputs with original infer
- Import network, perform inference. Compare outputs with previous ones

* Fix Centos build warnings
Myriad: reset executableNetwork before next load
Myriad: Reduced time consumption for Myriad tests

* Caching test suite - batch size parameter support

docs/template_plugin/tests/functional/shared_tests_instances/behavior/caching_tests.cpp

@@ -0,0 +1,25 @@
+// Copyright (C) 2021 Intel Corporation
+// SPDX-License-Identifier: Apache-2.0
+//
+
+#include "behavior/caching_tests.hpp"
+
+using namespace LayerTestsDefinitions;
+
+namespace {
+    static const std::vector<ngraph::element::Type> precisionsTemplate = {
+            ngraph::element::f32,
+    };
+
+    static const std::vector<std::size_t> batchSizesTemplate = {
+            1, 2
+    };
+
+    INSTANTIATE_TEST_CASE_P(smoke_CachingSupportCase_Template, LoadNetworkCacheTestBase,
+                            ::testing::Combine(
+                                    ::testing::ValuesIn(LoadNetworkCacheTestBase::getStandardFunctions()),
+                                    ::testing::ValuesIn(precisionsTemplate),
+                                    ::testing::ValuesIn(batchSizesTemplate),
+                                    ::testing::Values(CommonTestUtils::DEVICE_TEMPLATE)),
+                            LoadNetworkCacheTestBase::getTestCaseName);
+} // namespace