Create outputs for the new results of the variables

[gnawin]

Add the following to outputs:

• assets_decommission_simple_method
• assets_decommission_compact_method
• and decommission for flow, assets_investment_energy (waiting for Add the simple method for investments in transport assets #792 Add the simple method for storage assets #806)

[gnawin]

Blocked by #792 #806

[gnawin]

This is more complex than expected, because assets_decommission_compact_method is a vector without information on the indices. It create trouble when we want to save solution to files.

Maybe it is better to do after the refactor.