Initial device provisioning, and handling wifi credential changes/updates

Posting this issue to start a discussion and get input from others currently using Homie as well, especially with plans to remove the proxy feature to remove bloat from firmware #473 which is really IMO just a "work around"

Initial Device Provisioning

1. How do you currently provision new devices? Just manually enter the details in captive portal? What about when you want a user to login to an account to associate a device, and generate an ID to use with the device?

WiFi AP/Credential Changes or Router Failure

1. How do you currently handle something like this? Do you just completely reset the device and configure it again?

Device Provisioning

So currently to provision a device you have the API endpoints or the captive portal while in configuration mode. Specifically for anybody that plans to use Homie for something other than basic home projects, there's no simple way to provision a device with a custom device ID.

Case and point, you have a separate web UI for managing devices. When a new device is setup you generate a unique ID for the device, and then either have to manually enter it in the captive portal, or come up with a hack to work around issues like Android not making calls to API endpoint because the homie device has no internet connection.

This is the reason that the proxy configuration was added, to facilitate the ability to provision a device without requiring the user to know what device ID (or even MQTT config) to enter, and to allow for using Homie in non-diy situations ... which IMO would only benefit Homie as it would gain more wide adoption.

WiFi AP/Credential Changes

Say your WiFi router craps out on you and you have to buy a new one, or cable company replaces it ... most end users just use the default included wifi creds, or AP name, so when this happens, your Homie device no longer works and the only way to fix it is to do a full reset on the device.

Same with if you (or your end client) decides to change their wifi password, or AP name ... most will forget to update any iot devices before doing this, and then end up in the same spot as above, as if AP router failed.

Yes this may be easy for those of us who are technically inclined, but say you wanted to use Homie for clients, you parents, or anybody else who is not technically inclined ... see what i mean?