Added ZHA support for the Ikea E2123 media remote

[harrismck]

I added ZHA support for the Ikea E2123 media remote. Tested with my own remote and homeassistant instance, seems to be working great! It's been a long time since I've written any python, so let me know if there's a better way to go about this (particularly the get_zha_action method).

[harrismck]

Not super important as part of this PR, but as noted in this comment #842 (comment), the release functionality doesn't work for holding the plus/minus buttons. I don't know if that's something we can fix though, as it seems no ZHA event is fired when you let go of those buttons...

Even fired when holding the + button (this is fired multiple times while held)

event_type: zha_event
data:
  endpoint_id: 1
  cluster_id: 8
  command: move
  args:
    - 0
    - 255
    - 0
    - 0
  params:
    move_mode: 0
    rate: 255
    options_mask: 0
    options_override: 0
origin: LOCAL
time_fired: "2025-01-05T23:27:38.287379+00:00"
context:
  id: 01JGWCQ9SFQ03RAWBG9NQ2YBCC
  parent_id: null
  user_id: null

Eventually, another event that looks like this will fire, but I think it's not useful as the volume will already be at max/min:

event_type: zha_event
data:
  device_ieee: b4:3a:31:ff:fe:30:85:b8
  unique_id: b4:3a:31:ff:fe:30:85:b8:2:0x0008
  device_id: 76ad5991b2f49d0160760495d7f64e7d
  endpoint_id: 2
  cluster_id: 8
  command: move_to_level_with_on_off
  args:
    - 254
    - 150
  params:
    level: 254
    transition_time: 150
origin: LOCAL
time_fired: "2025-01-05T23:28:52.866734+00:00"
context:
  id: 01JGWCSJM24MKZJV5NJWS6YD3G
  parent_id: null
  user_id: null

For now, a workaround can be to use merge-mapping to map some other button to the media_player_release action I guess...