[IDEA] router.routeMessage should populate sourceMap "sourceChannelID" like a channel writer destination

[pacmano1]

Is your feature request related to a problem? Please describe.
When using router.route, unless you manually build the source map, the destination channel does not indicate on a message what channel sent the message. A channel writer does automatically add a sourceMap entry

Describe your use case
I need this feature so I can accomplish:

1. controlling in a destaintion channel what channel(s) are allowed to send it it
2. answering questions like "what channel sent me this message"

Describe the solution you'd like
For the router.route, automaitcally add the sender channel ID (and name) to the sourceMap.

Describe alternatives you've considered
Obviously I can build that sourceMap, but it should be passive.

Additional context

[MichaelLeeHobbs]

/**
 * Route a JSON message to channel by channel id and include the metadata for tracking message flow
 * @param {string} cid
 * @param {Object} json
 */
const routeJsonMsg = (cid, json) => {
  if (!json.metadata) {
    json.metadata = {}
    var sourceChannelIds = sourceMap.get('sourceChannelIds') || sourceMap.get('sourceChannelId')
    var sourceMessageIds = sourceMap.get('sourceMessageIds') || sourceMap.get('sourceMessageId')
    if (sourceChannelIds && sourceMessageIds) {
      json.metadata.sourceChannelIds = sourceChannelIds.toArray ? sourceChannelIds.toArray() : [sourceChannelIds]
      json.metadata.sourceMessageIds = sourceMessageIds.toArray ? sourceMessageIds.toArray() : [sourceMessageIds]
      json.metadata.sourceChannelNames = json.metadata.sourceChannelIds.map(id => ChannelUtil.getChannelName(id))
    } else {
      json.metadata.sourceChannelIds = []
      json.metadata.sourceMessageIds = []
      json.metadata.sourceChannelNames = []
    }
  }
  json.metadata.channelId = channelId
  json.metadata.channelName = channelName
  json.metadata.messageId = connectorMessage.getMessageId()
  json.metadata.errorMessage = json.errorMessage || ''
  json.metadata.errorStack = json.errorStack || ''

  json.metadata.sourceChannelIds.push(channelId)
  json.metadata.sourceMessageIds.push(json.metadata.messageId)
  json.metadata.sourceChannelNames.push(channelName)
  router.routeMessageByChannelId(cid, JSON.stringify(json, null, 2))
}

/* globals router, connectorMessage, channelId, channelName, sourceMap, ChannelUtil, */

[anibal2j]

This is exactly the same thing I'm looking for.