Rigidbody2D.Slide API does not have the needed configuration when creating a 2D Top-Down character controller

Reproduction steps:
1. Open the attached “IN-91716.zip” project
2. Open the “SampleScene” Scene
3. Enter the Play mode
4. Move around with WASD keys

Expected result: The character slides along surfaces on all axes
Actual result: Configuration for sliding along all surfaces and axes is not suitable for a 2D top-down character controller

Reproducible with: 6000.0.33f1, 6000.1.0b1
Couldn't test with: 2021.3.47f1, 2022.3.55f1 (Rigidbody2D.Slide functionality was released in 2023.1)

Reproducible on: Windows 11
Not reproducible on: no other environment tested

Notes:

• User was asked by a developer to submit this issue from the discussions page: https://discussions.unity.com/t/2d-top-down-character-controller-using-rigidbody2d-slide/1574182
• Issue likely arises due to Rigidbody2D.SlideMovement.surfaceUp configuration requiring a non-zero-vector value