add dynamic options for cache (#4894)

* add dynamic options for cache

* fixed bugs based on unit-test

* add doc for cache

* make cache implements be private

* Change simpleCache name to InMemoryCache

Signed-off-by: Wenhao Zhou <wenhaozhou@yunify.com>

* Remove fake cache and replacing to in memory cache with default parameter

Signed-off-by: Wenhao Zhou <wenhaozhou@yunify.com>

Signed-off-by: Wenhao Zhou <wenhaozhou@yunify.com>

pkg/simple/client/kiali/client_test.go

@@ -38,6 +38,11 @@ func TestClient_Get(t *testing.T) {
 	type args struct {
 		url string
 	}
+
+	inMemoryCache, err := cache.NewInMemoryCache(nil, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
 	token, _ := json.Marshal(
 		&TokenResponse{
 			Username: "test",
@@ -92,7 +97,7 @@ func TestClient_Get(t *testing.T) {
 			name: "Token",
 			fields: fields{
 				Strategy: AuthStrategyToken,
-				cache:    cache.NewSimpleCache(),
+				cache:    inMemoryCache,
 				client: &MockClient{
 					TokenResult:   token,
 					RequestResult: "fake",