STY: values being popped and reset when writing files

[jklenzing]

Is your feature request related to a problem? Please describe.
A number of parameters are popped in to_netcdf and rewritten by pysat. These include
'Date_End', 'Date_Start', 'File', 'File_Date', 'Generation_Date', 'Logical_File_ID'

Describe the solution you'd like
This may be unnecessary since the variables are rewritten. Preliminary tests suggest so.

Describe alternatives you've considered
Could be necessary in some cases. Maintain belt and braces to ensure these params are always accurate.

Additional context
Discovered in the context of #1117