let selectPlots properly work with coupled runs

[orichters]

Purpose of this PR

• needs make sure totals in showAreaAndBarPlots always find area plots pik-piam/mip#111
• slight adjustment to script that was just introduced in add selectPlots output script #1815
• overwrite model name with "REMIND", if not, plotIntercomparison thinks REMIND and MAgPIE are two different models and always puts the model name in front of all scenarios so you can't read the plot labels anymore.

Type of change

• Bug fix

Checklist:

• My code follows the coding etiquette
• 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)
• No need to update the changelog CHANGELOG.md