Deprecate Authentication=ActiveDirectoryPassword

[David-Engel]

Given the direction of Azure authentication and enforcement of mandatory MFA, we should deprecate the ActiveDirectoryPassword Authentication option on SqlConnections. MSAL.NET and Azure.Identity are also going to deprecate their corresponding APIs.

For more details of the Azure plan, see Planning for mandatory multifactor authentication for Azure and other admin portals

I imagine this includes annotating:

public enum SqlAuthenticationMethod
{
    [Obsolete("ActiveDirectoryPassword is deprecated.")]
    ActiveDirectoryPassword

Updating the API docs (SqlAuthenticationMethod.xml), public docs, and including it in the next release announcement.

Let me know if I'm missing anything else.

[ErikEJ]

Maybe some connection string docs?