Integer volume fractions in .silo file discarded after loading with Conduit Relay

[JustinPrivitera]

https://teams.microsoft.com/l/message/19:f2ed7be3682d40d1b8e038744e500a09@thread.skype/1755812749317?tenantId=a722dec9-ae4e-4ae3-9d75-fd66e2680a63&groupId=70162982-9587-4bcc-ad53-20178c76fe11&parentMessageId=1755812749317&teamName=VisIt&channelName=General&createdTime=1755812749317

Need to support integer volume fractions in the silo reader.

[JustinPrivitera]

Add more cases here: https://github.com/LLNL/conduit/blob/085e2fee683c41d3067e7f6b6f1c61654a29d5d0/src/libs/relay/conduit_relay_io_silo.cpp#L2781