Add multiselect for updating devices

**Describe the problem you have/What new integration you would like**

At the moment if you have a group of devices to update and only one (or a few) device you don’t want updated then each one has to be individually updated manually, wait for the update of that device, when done then update the next device manually and so on. You can’t use the “Update All” button. This takes a lot of time.

**Please describe your use case for this integration and alternatives you've tried:**

When updating multiple devices it would be nice to be able to select (tick box) the devices you would like to be updated and click a (one) button and it will start the update of all selected devices. Just like the “update All” button but it will only update the devices you selected.

This way it would be easer/faster to update the devices you would like and not the ones you don’t want updated in one click. You then can just walk away and let it do it’s updates.

**Additional context**

I for example have some sonoff basic devices which I don't update because they normally don't connect to WIFI afterwards. So I must update all the other 20 devices one by one.

P.s.: Thanks Blacky for most of this text!

No files or tests are named. Start by locating the existing “Update All” button and device-update workflow, then determine how device selection is represented. Done means selected devices can be updated together while unselected devices are skipped.

Written by the indexing model from the issue text.