[Blazor] Add a way to indicate event handler should not call StateHasChanged

[mrpmorris]

When adding @onmousemove=MouseHasMoved to an element Blazor will re-render the component every time the MouseHasMoved method finishes executing.

Preventing this using ShouldRender is tricky, because the component might need to render for other reasons, and having to set some state for every scenario that causes a re-render is labourious.

Could we have a way of telling Blazor not to add a call to StateHasChanged. Perhaps something like this

@onmousemove:preventStateHasChanged
@onmousemove:preventStateHasChanged=true
@onmousemove:preventStateHasChanged=LeftMouseButtonIsHeldDown

[mkArtakMSFT]

Thanks for contacting us.
This is a dupe of #18919