add |+| to 'Energy Investments', remove DAC from Electricity, rename |Elec| to Electricity

[orichters]

• Energy Investments had a summation issue: https://github.com/remindmodel/development_issues/issues/265
• Turns out: this line calculating Energy Investments|Electricity also sums over dac which is part of tenotransform which is added here, while this is no sub-category of Energy Investments|Elec|*. So I removed the CCS technologies from the Electricity summation
• At some later point, the Energy Investments|Demand|* chain might be populated with (not only) the CDR data
• Added |+| notation and additional summation checks
• In renamed Energy Investments|Elec to Energy Investments|Electricity like all the parent category. This will need some fixes to the piamInterfaces mappings to keep backwards compatibility. Also did that for Operational costs|Elec|wind and Total Energy costs|Elec|Biomass
• One issue: the old gdx from the last REMIND release fails on one of them, but the newest AMTs don't. Probably, there was something fixed in REMIND in between.
• in cs2, rename all incoming |Elec| to |Electricity| to allow for backwards compatibility

See

devtools::load_all("/p/tmp/oliverr/piamInterfaces")
devtools::load_all("/p/tmp/oliverr/remind2")
gdx <- "/p/projects/remind/runs/REMIND_2024_03_24/remind/output/SSP2EU-PkBudg650_2024-03-24_20.02.18/fulldata.gdx"
d <- checkSummations(reportEnergyInvestment(gdx), outputDirectory = NULL, summationsFile = "extractVariableGroups")
d <- checkSummations(reportEnergyInvestment(gdx), outputDirectory = NULL, summationsFile = "/p/tmp/oliverr/remind2/inst/extdata/additional_summation_checks.csv")