feat(runner): expose the method process

[akkuman]

expose the mothod process to support the pipeline pattern, like https://go.dev/blog/pipelines

this is a example:

func run(inCh chan string) (outCh chan runner.Result) {
	threadCount := 50
	opt := &runner.Options{
		Methods: "GET",
		Threads: threadCount,
	}
	rr, err := runner.New(opt)
	if err != nil {
		panic(err)
	}
	wg := sizedwaitgroup.New(threadCount)
	scanopts := rr.GetScanOpts()
	outCh = make(chan runner.Result, 1000)
	go func() {
		defer close(outCh)
		for target := range inCh {
			rr.Process(target, &wg, httpx.HTTPorHTTPS, &scanopts, outCh)
		}
		wg.Wait()
	}()
	return outCh
}