libbluetooth: Add BT_STATUS_SOCKET_ERROR metric

Add granularity to BT_STATUS_FAIL error codes by introducing a new
BT_STATUS_SOCKET_ERROR metric, to be used when an effort to find a
device by address or other identifier fails.

Bug: 340296381
Test: m -j
Flag: Exempt, metrics-only change

Change-Id: I030ea3e1545d6979f3634d89d3d6aefbdca619b2