Remove the 'show password' approach in the `PasswordEntry` components

[guardrex]

Although it still works in Edge, let's remove the 'show password' approach in the PasswordEntry components because browsers (e.g., Firefox) block manipulation of the type attribute these days. One has to flip in and out of a different <input> elements to make it work, and this is beyond what the example is focused on demonstrating.

Confirm that the change doesn't require article changes.

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• Content Source: dotnet/blazor-samples
• GitHub Login: @guardrex