fixed rare infeasibility in peatland "on" realization

[flohump]

🐦 Purpose of this PR 🐦

• In some runs I encountered feasibility issues in the peatland "on" module realization
• These problems are likely caused by small differences in accuracy between variables and parameters in GAMS
• I introduced two balancing variables with a high cost factor to avoid these infeasibilities

🔧 Checklist for PR creator 🔧

• Labeling pull request correctly from the label list.

• Low risk : Simple bugfixes (missing files, updated documentation, typos) or Start/output scripts
• Medium risk : New realization / Changes to existing realization / Other changes which don't modify default.cfg
• High risk : New input files (if cfg$input is changed in default.cfg) / Modification to core model (eg. changes in equations, calculations, introduction of new sets etc.) / Other changes in default.cfg

• Providing additional information based on PR label

• Low risk : No new model run needed.
• Medium risk : Default run based on the current version of the fork from which PR is made
• High risk
  • Default run from the current develop branch ("_before")
  • Default run based on the current version of the fork from which PR is made ("_after")

• 📉 Performance loss/gain from current default behavior 📈
  • Current develop branch default : 0.5 h
  • This PR's default : 0.48 h

• Added changes to CHANGELOG.md
• Compilation check (model starts without compilation errors - use gams main.gms action=c in model folder for testing).
• No hard coded numbers and cluster/country/region names.
• The new code doesn't contain declared but unused parameters or variables.
• Where relevant, In-code comments added including documentation comments.
• Made sure that documentation created with goxygen is okay (use goxygen::goxygen() for testing).
• Changes to magpie4 R library for post processing of model output (ideally backward compatible).
• Self-review of my own code.
• For high risk runs: validation of major model indicators - Land-use, emissions, food prices, Tau. %Delete this line in case it is not a high risk run%

⚠️ Additional notes or warnings ⚠️

NA

🚨 Checklist for RSE reviewer 🚨

• PR is labeled correctly.
• CHANGELOG is updated correctly
• No hard coded numbers and cluster/country/region names.
• No unnecessary increase in module interfaces
• All required updates in interfaces (if any) have been properly adressed in the module contracts
• In-code comments and documentation comments are satisfactory.
• model behavior/performance is satisfactory.
• Requested changes (if any) were applied correctly

🚨 Checklist for MAgPIE reviewer 🚨

• PR is labeled correctly.
• CHANGELOG is updated correctly
• No hard coded numbers and cluster/country/region names.
• Changes to the model are scientifically sound
• In-code comments and documentation comments are satisfactory.
• model behavior/performance is satisfactory.
• Requested changes (if any) were applied correctly

[abhimishr]

Good to go after default config update

[abhimishr]

I think the new scalar introduced here can also be added to default config (as other scalars are also in the default config already from this realization). Other than that, good to go!

[abhimishr]

good to go 👍🏽