Feature request: Possibility to add continuation with parent job result as input parameter.

Would it be feasible to extend the BackgroundJob interface with something like:

`string ContinueJobWithResult(string parentId, Expression> methodCall);`

which could be used like this:

`string jobId = BackgroundJob.Enqueue(x => x.CalculateValue());`
`BackgroundJob.ContinueWithResult((x, result) => x.UseValue(result));`

The goal here is to be able to separate job methods from the invokation process, i.e. using methods as is, without having to deal with [ContinuationsSupport] and injecting PerformContext arguments into code.

Start by reviewing the BackgroundJob interface and the existing continuation support referenced in the issue. Trace how parent job results and method expressions are currently handled, then identify the tests covering continuations. Done means the requested continuation API behavior is defined and verified without requiring job methods to accept PerformContext.

Written by the indexing model from the issue text.