Factor in reverse pusher delay on mission acceptance radius

[sanderux]

When using reverse thrust to brake and setting a reverse thrust delay this should be factored in to the acceptance radius of a vtol_land mission item.

[sanderux]

test flown, works as expected: https://logs.px4.io/plot_app?log=947c9718-d299-472f-9333-0d5cec440dbc

[dagar]

This is fine for now, but we should start thinking about a more general pattern for this kind of thing.
Navigator should be agnostic to vehicle specifics. For example FW broadcasts a status message that navigator uses for acceptance radius. It seems like VTOL should be doing the same. If the land detector becomes "vehicle mode" that might be an appropriate home.

[dagar]

Is any of this interfering with tailsitter or tiltrotor?