Remove ECEMF scenarios (they are only used in EDGE-T standalone)

[johannah-pik]

Purpose of this PR

This PR

1. Removes the ECEMF scenarios. So far they are not used in REMIND (only in EDGE-T standalone) and they have no associated REMIND demand scenario that is coordinated with other sectors.
2. Removes edge-t internal demand scenario SSP2EU_demRedStrong from REMIND demand scenarios

This PR is connected to PR#549 in mrremind

Type of change

(Make sure to delete from the Type-of-change list the items not relevant to your PR)

• [x ] Bug fix
• Refactoring
• New feature
• Minor change (default scenarios show only small differences)
• Fundamental change
• This change requires a documentation update

Checklist:

• [ x] My code follows the coding etiquette
• [ x] I performed a self-review of my own code
• 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 the reporting in remind2 where it was needed
• I adjusted forbiddenColumnNames in readCheckScenarioConfig.R in case the PR leads to deprecated switches
• All automated model tests pass (FAIL 0 in the output of make test)
• The changelog CHANGELOG.md has been updated correctly

Further information (optional):

• Test runs are here:
• Comparison of results (what changes by this PR?):

[johannah-pik]

@LaviniaBaumstark brauchen wir jetzt schon neue input daten, damit es keinen domain error gibt wenn wir die szenarien entfernen?

[LaviniaBaumstark]

ja, genau, das kann erst gemert werden, wenn wir neue input daten haben.