New feature. "fail/cancel-immediately-if-locked"

[lurbanski-equinix]

Hi,

When we have manually triggered workflows which last very long. There is a need to have a lock, but is not useful to wait for it endlessly. For example when somebody would trigger manually soak tests again by mistake.

I propose to create a parameter "fail/cancel-immediately-if-locked" with default false value or "wait-for-lock" with default "true" value.