Add a HTTP cache for remote resources.

Fixes #12502
Closes #11891

common/maps/maps.go

@@ -112,17 +112,17 @@ func ToSliceStringMap(in any) ([]map[string]any, error) {
 }
 
 // LookupEqualFold finds key in m with case insensitive equality checks.
-func LookupEqualFold[T any | string](m map[string]T, key string) (T, bool) {
+func LookupEqualFold[T any | string](m map[string]T, key string) (T, string, bool) {
 	if v, found := m[key]; found {
-		return v, true
+		return v, key, true
 	}
 	for k, v := range m {
 		if strings.EqualFold(k, key) {
-			return v, true
+			return v, k, true
 		}
 	}
 	var s T
-	return s, false
+	return s, "", false
 }
 
 // MergeShallow merges src into dst, but only if the key does not already exist in dst.