feat: add features to conformance and do some refactors (#532)

Signed-off-by: bitliu <bitliu@tencent.com>

test/e2e/conformance/tests/tests.go

@@ -0,0 +1,26 @@
+// Copyright (c) 2022 Alibaba Group Holding Ltd.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package tests
+
+import "github.com/alibaba/higress/test/e2e/conformance/utils/suite"
+
+func Register(testcase suite.ConformanceTest) {
+	if len(testcase.Features) == 0 {
+		panic("must set at least one feature of the test case")
+	}
+	ConformanceTests = append(ConformanceTests, testcase)
+}
+
+var ConformanceTests []suite.ConformanceTest