Dynamically updating labels

[simonziegler]

A feature requested by @stefanloerwald is that Labels should have the capability to be updated after first render. A use case is multi-lingual support.

Initial investigation shows this to be very complex, in particular with floating labels and notched outlines. This may not be reasonably achievable for Material.Blazor with a workaround being for the caller to force a re-render when labels need to change. Maybe this can be done by using @key on a component and linking this to the value of the Label.

Reference material-components/material-components-web#6546

[simonziegler]

Added to material-components-web backlog.

[simonziegler]

This should naturally get fixed with migration to Material 3. See #795.