device: remove buttonGroupMembership field

buttonGroupMembership is stored in config bank:3 index:0x01 4 high bits buttonActiveGroup is stored in config bank:3 index:0x1d

Historically, buttonGroupMembership was first. It was replaced later by 8-bit buttonActiveGroup, but buttonActiveGroup is not persistenly stored by old terminal blocks.

Both config bytes are being updated in dsm by dsm-api call DeviceProperties_set_button_active_group. So, for groups < 16, they are usually in sync.

But buttonGroupMembership shares the config register with buttonId. When dss needs to update buttonId, it uses its own cached copy of buttonGroupMembership to create config bank:3 index:0x01 value. This leads to race conditions, because the cache may be outdated.

In fact, the buttonGroupMembership cached copy in dss was updated only on an config event from dsm or in device readout in BusScanner. This makes the race window quite big.

We remove buttonGroupMembership field as it does not carry any additional information. We use buttonActiveGroup that is synchronously updated from when calling DeviceProperties_set_button_active_group.

The race condition still exists. E.g. when setDeviceButtonId is called during device readout. But it is much harder to trigger now. To fully remove the race condition, we must either

1. store only 0 for buttonGroupMembership in config bank:3 index:0x01
2. combine button group and button id only in dsm, never in dss. That require to introduce and use new dsm-api method DeviceProperties_set_button_id and use it instead of DeviceConfig_set_sync

ref #17170