cleanup unused variables and change Clab.WithRuntime(...) to use *runtime.RuntimeConfig

[steiler]

the Clab bound options where not used any more. Hence I've deleted them.
changed Clab.WithRuntime from (name string, d bool, dur time.Duration, gracefulShutdown bool) to (name string, rtconfig *runtime.RuntimeConfig).

[steiler]

We can discuss if we should use a copy of the runtimeConfig provided to avoid any race conditions.
On the other hand one could use that handle to change runtime config by intention.
Unsure myself.

[hellt]

1. as to the removed options, we need to see why they were not used anymore. Both graceful shutdown and debug were used before
2. now when I see the full PR I am not sure it is a good idea to import runtime package for cmd package
   wdyt @karimra ?

[karimra]

1. I think the values are still used, they just moved to runtimeConfig
2. I think it's ok, as long as runtime and clab do not import cmd, it should be cycle free

[steiler]

Also the debug variable, is just consumed in one case by the docker runtime.

containerlab/runtime/docker/docker.go

Lines 221 to 226 in fa9c2da

	if c.config.Debug {
	log.Debugf("network '%s' has %d active endpoints, deletion skipped", c.Mgmt.Network, numEndpoints)
	for _, endp := range nres.Containers {
	log.Debugf("'%s' is connected to %s", endp.Name, network)
	}
	}

And even this can be left out, since this is omitted via the debug level, which even used the global debug var.
To be honest that flag is not really needed atm.

[hellt]

Also the debug variable, is just consumed in one case by the docker runtime.

the debug is used not only in docker, it is also used in ignite

containerlab/runtime/ignite/iginite.go

Line 239 in 4caa86f

vmChans, err := operations.StartVMNonBlocking(vm, c.config.Debug)

[hellt]

but the rest looks ok to me
Building the binary with -race doesn't detect any issues with passing runtime config as a pointer, so should be ok as well