Use React's context to track how many CRs are moved into their next
state with conflicts present.
This PR wraps environment change requests and change request overviews
in a change request plausible context that contains a
`willOverwriteStrategyChanges` property. This property is updated by the
diff calculation if there are any conflicts and then read by the
`changeState` function in the `useChangeRequestApi` hook.
As long as at least one of the strategies in the CR contain conflicts,
it will be marked as overwriting changes.
