feat: adds path translation from v3 to v2 for validation errors

Signed-off-by: Vincent Biret <vibiret@microsoft.com>

Author: baywet

src/Microsoft.OpenApi/PublicAPI.Unshipped.txt

@@ -1 +1,4 @@
 #nullable enable
+Microsoft.OpenApi.OpenApiPathHelper
+static Microsoft.OpenApi.OpenApiPathHelper.GetVersionedPath(string! path, Microsoft.OpenApi.OpenApiSpecVersion targetVersion) -> string?
+Microsoft.OpenApi.OpenApiValidatorError.GetVersionedPointer(Microsoft.OpenApi.OpenApiSpecVersion targetVersion) -> string?

src/Microsoft.OpenApi/Services/IOpenApiPathRepresentationPolicy.cs

@@ -0,0 +1,24 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT license.
+
+namespace Microsoft.OpenApi;
+/// <summary>
+/// Defines a policy for matching and transforming OpenAPI JSON Pointer paths
+/// between specification versions.
+/// </summary>
+internal interface IOpenApiPathRepresentationPolicy
+{
+    /// <summary>
+    /// Determines whether this policy can handle the given path.
+    /// </summary>
+    /// <param name="path">The JSON Pointer path to evaluate.</param>
+    /// <returns><c>true</c> if this policy applies to the given path; otherwise, <c>false</c>.</returns>
+    bool IsMatch(string path);
+
+    /// <summary>
+    /// Transforms the given path to its equivalent in the target specification version.
+    /// </summary>
+    /// <param name="path">The JSON Pointer path to transform.</param>
+    /// <returns>The transformed path, or <c>null</c> if the path has no equivalent in the target version.</returns>
+    string? GetVersionedPath(string path);
+}