[v9.3.x] CloudWatch: Cross-account querying support (#59389)

* add cross-account querying support

* fix tests

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

@@ -0,0 +1,53 @@
+package resources
+
+import (
+	"fmt"
+	"net/url"
+	"strconv"
+)
+
+const defaultLogGroupLimit = int64(50)
+
+type LogGroupsRequest struct {
+	ResourceRequest
+	Limit                                   int64
+	LogGroupNamePrefix, LogGroupNamePattern *string
+}
+
+func (r LogGroupsRequest) IsTargetingAllAccounts() bool {
+	return *r.AccountId == "all"
+}
+
+func ParseLogGroupsRequest(parameters url.Values) (LogGroupsRequest, error) {
+	logGroupNamePrefix := setIfNotEmptyString(parameters.Get("logGroupNamePrefix"))
+	logGroupPattern := setIfNotEmptyString(parameters.Get("logGroupPattern"))
+	if logGroupNamePrefix != nil && logGroupPattern != nil {
+		return LogGroupsRequest{}, fmt.Errorf("cannot set both log group name prefix and pattern")
+	}
+
+	return LogGroupsRequest{
+		Limit: getLimit(parameters.Get("limit")),
+		ResourceRequest: ResourceRequest{
+			Region:    parameters.Get("region"),
+			AccountId: setIfNotEmptyString(parameters.Get("accountId")),
+		},
+		LogGroupNamePrefix:  logGroupNamePrefix,
+		LogGroupNamePattern: logGroupPattern,
+	}, nil
+}
+
+func setIfNotEmptyString(paramValue string) *string {
+	if paramValue == "" {
+		return nil
+	}
+	return &paramValue
+}
+
+func getLimit(limit string) int64 {
+	logGroupLimit := defaultLogGroupLimit
+	intLimit, err := strconv.ParseInt(limit, 10, 64)
+	if err == nil && intLimit > 0 {
+		logGroupLimit = intLimit
+	}
+	return logGroupLimit
+}