rename EDGET Vars

[jmuessel]

Purpose of this PR

During the edgeT refactoring we changed variable names and, accordingly, did this as well in piamInterfaces and remind2 (see PR).
I will only merge this PR AFTER the refactoring is merged and want to prepare this PR now to follow up quickly.

In addition, I deleted missing variables from the AR6 mapping, as requested in this issue.

• Emi|CO2|Transport|Freight|Short-Medium Distance|Demand (Mt CO2/yr)
• Emi|CO2|Transport|Pass|Short-Medium Distance|Demand (Mt CO2/yr)
• UE|per capita|Transport|Pass (GJ/cap/yr)

Checklist:

• I did not use Excel to open csv files or checked that no side-effects occur (changed values, many new quotation marks, …)
• I added any renamed piam_variable to renamed_piam_variables.csv to guarantee backwards compatibility.

It is recommended to have a look at the tutorial before submission.

This PR will be merged with several other PRs related to the switch to edgeTransport 2.0:

• edgeTransport #266
• reporttransport #18
• mrremind #542
• remind #1749
• remind2 #642

[orichters]

Thanks. Might you have a look at pik-piam/edgeTransport#244 and remove all piam_variables in the AR6 template that are not provided by EDGE-T anymore (or never were)?

[jmuessel]

@orichters I deleted some variables according to the issue you mentioned and integrated your changes from today in the navigate template. Do you think we are ready to merge now? Of course after the edgeT-merge, which will introduce the new variable names.

[orichters]

If make test works, we are good to go, I think.