Unifying error descriptions for client authentication failures

[piraveena]

Current Limitation

The following error description is shown when an incorrect client id is given in the token request.

A valid OAuth client could not be found for client_id: <client_id>

And the following error description is shown when correct client id and incorrect client secret is given in the token request.

Client credentials are invalid

Suggested Improvement

We need to unify these 2 error messages as an improvement to the product.

Version

No response