Multiple listeners for ImageRequest

[Koitharu]

Is your feature request related to a problem? Please describe.
Support for multiple listeners for ImageRequest

Describe the solution you'd like
Now ImageRequest.Builder allow to set only one Listener, so call listener() overrides previous listener value. It would be nice to add something like addListener()

Additional context
None

[l2hyunwoo]

Can I take this issue?

[colinrtwhite]

Would creating your own composite listener fulfill this use case?

class CompositeListener : ImageRequest.Listener {
    val listeners = mutableListOf<ImageRequest.Listener>()

    override fun onStart(request: ImageRequest) {
        listeners.forEach { it.onStart(request) }
    }

    override fun onCancel(request: ImageRequest) {
        listeners.forEach { it.onCancel(request) }
    }

    override fun onSuccess(request: ImageRequest, result: SuccessResult) {
        listeners.forEach { it.onSuccess(request, result) }
    }

    override fun onError(request: ImageRequest, result: ErrorResult) {
        listeners.forEach { it.onError(request, result) }
    }
}