DcmSend: abort associations when I/O errors on C-STORE mid transfer

[Enet4]

This PR addresses an edge case where a remote transfer association can hang indefinitely due to errors in the storage provider, such as corrupted storage data. Getting an IOException while invoking cstore would result in the local store SCU proceeding to wait for a response from the SCP, even though it had not sent the final PData, resulting in both peers waiting for each other.

The approach adopted here was to abort the association as soon as an IOException happens.