Re #7987. Simplified the filterwall usage for characterizations.
Re #7987. Removing cut-and-paste code.
Re #7987. Small changes to reduction script.
Re #7987. Removed noise run option from SNSPowderReduction.
Re #7987. Simpler check for eventworkspace.
Re #7987. All data is normalized by pcharge now.
Re #7987. Making the chunking workspace far more temporary.
Re #7987. Removing the last little bits of the vanadium noise run.
Re #7987. Moved vanadium correction to be before focusing the data.

This does break all of the chunking work for vanadium and its
background. Hopefully we can get this back soon.
Re #7987. Always load the vanadium background, use it, and delete it.
Merge branch 'feature/7987_powder_refactor' into develop