🐦 Description of this PR 🐦

This PR adds the fbask_jan16_sticky realization to the livestock module. It is a "sticky" version of the fbask_jan16 realization, that uses the (simplified) methodology of the sticky_feb18 factor cost realization for it's factor costs calculation.

The documentation describes the difference to fbask_jan16 as follows:

In this realization the capital share of livestock production cost does not have 
to be paid every timestep, but is fulfilled by having a corresponding capital stock,
which mostly persists across timesteps. (See `s70_depreciation_rate`)
This means that the production becomes cheaper in regions with
higher capital shares and existing corresponding capital stocks,
which makes the livestock production "stick" to some degree to existing levels. 
Another effect is that production increases are more likely to occur in regions
of more capital intensive livestock systems with already established stocks.

The realization is based on the `sticky_feb18` factor cost realization, but
also differs from it in some ways. At the creation time the main differences were: 
1. capital stocks are on the regional level not on cluster level
2. no differentiation of mobile and immobile capital - all capital stocks are immobile

🔧 Checklist for PR creator 🔧

• Label pull request from the label list.

  • Low risk: Simple bugfixes (missing files, updated documentation, typos) or changes in start or output scripts
  • Medium risk: Uncritical changes in the model core (e.g. moderate modifications in non-default realizations)
  • High risk: Critical changes in model core or default settings (e.g. changing a model default or adjusting a core mechanic in the model)

• Self-review own code

  • No hard coded numbers and cluster/country/region names.
  • The new code doesn't contain declared but unused parameters or variables.
  • magpie4 R library has been updated accordingly and backwards compatible where necessary.
  • scenario_config.csv has been updated accordingly (important if default.cfg has been updated)

• Document changes

  • Add changes to CHANGELOG.md
  • Where relevant, put In-code documentation comments
  • Properly address updates in interfaces in the module documentations
  • run goxygen::goxygen() and verify the modified code is properly documented

• Perform test runs

  • Low risk:
    • Run a compilation check via Rscript start.R --> "compilation check"
  • Medium risk:
    • Run test runs via Rscript start.R --> "test runs"
    • Check logs for errors/warnings
  • High risk:
    • Run test runs via Rscript start.R --> "test runs"
    • Check logs for errors/warnings
    • Default run from the PR target branch for comparison
    • Provide relevant comparison plots (land-use, emissions, food prices, land-use intensity,...)

📉 Performance changes 📈

• Current develop branch default (gams execution): 20.0 mins
• This PR's default : 19.5mins

🚨 Checklist for reviewer 🚨

• PR is labeled correctly
• Code changes look reasonable
  • No hard coded numbers and cluster/country/region names.
  • No unnecessary increase in module interfaces
  • model behavior/performance is satisfactory.
• Changes are properly documented
  • CHANGELOG is updated correctly
  • Updates in interfaces have been properly addressed in the module documentations
  • In-code documentation looks appropriate
• content review done (at least 1)
• RSE review done (at least 1)