Update MCPGraphing for SetUnitVariable & exit codes

refs #6386

Display variable and variableValue or microservicechainlink (whichever
is set) for task type SetUnitVariable, as well as non-0 exit codes from
MicroServiceChainLinks. Nodes that start chains are bordered in dark
gold.
Add AIP reingest button

refs #6488

Add Reingest button to the archival storage tab which POSTs to the
storage service reingest endpoint.  Add reingest form and storage
service helper to support this