Make NDC target emissions scope independent of multigasscen switch and do some further clean up of NDC realization

[fschreyer]

Purpose of this PR

This PR addresses https://github.com/remindmodel/development_issues/issues/794 and does some clean-up of the NDC code.

These are the changes:

• NDC-LTS sees right NDC targets again: emissions to use for checking whether NDC targets are reached always come in the same correct metric of the implementation (Emi|GHG|w/o Bunkers|w/o Land-use Change) independent of cm_multigasscen -> as NDC-LTS uses different multigasscen setting this led to wrong results in this scenario before (too ambitious NDC targets)
• increased carbon price limit of EU in 2030 to 200 $/tCO2 (to not be below NPI price)
• switched NDC target convergence check on again
• removed US from overall NDC target algorithm (will see exactly the same CO2 price instead of trying to reproduce NPi emissions) -> this led to convergence issues as "US target" for REMIND was sometimes not met
• let rescaling factors of co2 prices converge a bit slower as it helped in some runs -> made the implementation more transparent by introducing p45_factorRescaleUpLimit etc. parameters to track when rescaling is capped
• do not check NDC target convergence in CO2 price limit runs
• deleted prepare_NDC.R script as it is not necessary anymore and all related code

Type of change

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Parts concerned

• ☑️: GAMS Code
• ☑️ R-scripts
• ◻️ Documentation (GAMS incode documentation, comments, tutorials)
• ◻️ Input data / CES parameters
• ◻️ Tests, CI/CD (continuous integration/deployment)
• ◻️ Configuration (switches in main.gms, default.cfg, and scenario_config*.csv files)
• ◻️ Other (please give a description)

Impact

• ☑️: Bug fix
• ☑️ Refactoring
• ◻️ New feature
• ◻️ Change of parameter values or input data (including CES parameters)
• ◻️ Minor change (default scenarios show only small differences)
• ◻️ Fundamental change of results of default scenarios

Checklist

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In the end all checkboxes must be ticked before you can merge.

• I executed the automated model tests (make test) after my final commit and all tests pass (FAIL 0)
• I adjusted the reporting in remind2 if and where it was needed
• I adjusted the madrat packages (mrremind and other packages involved) for input data generation if and where it was needed
• My code follows the coding etiquette
• I explained my changes within the PR, particularly in hard-to-understand areas
• I checked that the in-code documentation is up-to-date
• I adjusted forbiddenColumnNames in readCheckScenarioConfig.R in case the PR leads to deprecated switches
• I updated the CHANGELOG.md correctly (added, changed, fixed, removed, input data/calibration)

Further information (optional)

• Runs with these changes are here:
• Comparison of results (what changes by this PR?):

[RahelMA]

Thank you, Felix, I'm not entirely done with you PR just note that we need p45_CO2eqwoLU_goal in the preloop!

[RahelMA]

I would argue we cannot remove this as we need the BAU data to calculate the NDC goal in the first place:

p45_CO2eqwoLU_goal(p45_NDCyearSet(t,regi)) =
          p45_EmiTargetAbs(t,regi)                                                  !! emissions target derived from countries with NDC target
        + (1-p45_shareTarget(t,regi)) * p45_BAU_reg_emi_wo_LU_wo_bunkers(t,regi);