[v9.3.x] CloudWatch: fix custom namespace for listing dimension keys, refactor to non-pointer types, add test assertions, rename packages (#59130)

CloudWatch: fix custom namespace for listing dimension keys, refactor to non-pointer types, add test assertions, rename packages (#59106)

Co-authored-by: Erik Sundell <erik.sundell87@gmail.com>
(cherry picked from commit c43e1a721f)

Co-authored-by: Shirley <4163034+fridgepoet@users.noreply.github.com>

pkg/tsdb/cloudwatch/models/resources/dimension_values_request.go

@@ -0,0 +1,37 @@
+package resources
+
+import (
+	"net/url"
+)
+
+type DimensionValuesRequest struct {
+	*ResourceRequest
+	Namespace       string
+	MetricName      string
+	DimensionKey    string
+	DimensionFilter []*Dimension
+}
+
+func GetDimensionValuesRequest(parameters url.Values) (DimensionValuesRequest, error) {
+	resourceRequest, err := getResourceRequest(parameters)
+	if err != nil {
+		return DimensionValuesRequest{}, err
+	}
+
+	request := DimensionValuesRequest{
+		ResourceRequest: resourceRequest,
+		Namespace:       parameters.Get("namespace"),
+		MetricName:      parameters.Get("metricName"),
+		DimensionKey:    parameters.Get("dimensionKey"),
+		DimensionFilter: []*Dimension{},
+	}
+
+	dimensions, err := parseDimensionFilter(parameters.Get("dimensionFilters"))
+	if err != nil {
+		return DimensionValuesRequest{}, err
+	}
+
+	request.DimensionFilter = dimensions
+
+	return request, nil
+}