Add bulk-edit for icons configuration

[abriemme]

It would save me (and others maybe) a lot time configuring entities icons in bulk.
For now i have to do it one by one.
We already have the capability to select multiple entities (to enable/disable in bulk).

I'm thinking something like:

[Wendelstein7]

Hi! I am very, very appreciative of all the work that people have put in the updates with mass selection of entities. This feature request is quite old, but I would like to bump it given the new context and actual developments, as this feature request is almost 3 years old.

Currently, you have a few options when selecting multiple entities on the top right: "Add label" and a triple-dot dropdown to manage enabledness and visibility. How cool would it be to also allow mass setting icons from here? It would greatly help me out, as I can easily query for specific entities using filters ad the search bar, and then set 40 or 50 icons at once instead of opening the dialog 40 to 50 times.

Let me know what you think! I tried to but didn't manage to succesfully setup the home assitant development on my local system so with my skill level unfortunately I am unable to help out myself. But perhaps someone who can would like this feature too! <3