Support new QE7.1 keywords and DFT+U specification in Nexus

[prckent]

Is your feature request related to a problem? Please describe.

QE7.1 changed how DFT+U is specified. This requires updates to Nexus to use and some strategy devised for use of older and newer versions.

Describe the solution you'd like

One including an error trap of mismatched options and versions, or an automatic upconversion if the implementations are compatible.

Describe alternatives you've considered None

Additional context

Would be ideal for next release but analysis needs to be done on how much work this is.