bluetooth: controller: fixed problems in ISO-AL RX

[*] Fixed setting of SDU production status when exiting the
    ISOAL_ERR_SPOOL state for framed PDU consumption when receiving the
    start of the next SDU
[*] Changed condition identifying a padding PDU to include padding PDUs
    with errors received after the end fragment is seen and expanded
    unit tests to cover new condition
[*] Changed definition of ISOAL_PDU_STATUS_xxx errors to match value of
    similar errors defined for the SDU status

Signed-off-by: Nirosharn Amarasinghe <niag@demant.com>