Support for decoding more than 2 digipeaters

Currently, the monitor only parses up to two digipeater addresses. This was based on an incorrect assumption that AX.25 supports a maximum of two digipeaters. In fact, the AX.25 spec allows for up to eight digipeater addresses.

For connected sessions, limiting to two digipeaters remains a practical best practice due to the limitations in handling acknowledgments and timeouts across multiple hops.

However, for UI frames (unconnected mode), this limitation is unnecessary since these frames are not acknowledged. The monitor should support decoding the full range of up to eight digipeaters allowed by the protocol.