add validation for intermediate scenario files

[jacobvjk]

closes ADO https://dev.azure.com/RMI-PACTA/2DegreesInvesting/_workitems/edit/7504

• adds a function validate_intermediate_scenario_output() which follows the structure of other validation functions
• it aims to validate the processed scenarios in their standardised format (still using absolute scenario values)
• these are then used as inputs for calculating TMSR/SMSP and SDA values
• validation includes:
  • required columns
  • column types
  • allowed categorical values and their combinations
  • expected ranges of values by sector and unit

[jdhoffa]

Unreal!!