fix tax convergence reporting in modelSummary

[orichters]

Purpose of this PR

• was broken since all iterations were tracked, as p80_convNashTaxrev was replaced by p80_convNashTaxrev_iter
• now again prints the following to the log and to remindstatus on the cluster:

  No failed markets in fulldata.gdx.
  Failed tax convergence in fulldata.gdx:
  - IND: 2080
  - MEA: 2070, 2080, 2090
  - REF: 2070, 2080, 2090, 2100, 2110, 2130, 2150
  - SSA: 2070, 2080

Type of change

• [x] Bug fix

Checklist:

• [x] My code follows the coding etiquette
• [x] I performed a self-review of my own code
• [x] I explained my changes within the PR, particularly in hard-to-understand areas
• [x] I checked that the in-code documentation is up-to-date
• [x] I adjusted the reporting in remind2 where it was needed
• [x] I adjusted forbiddenColumnNames in readCheckScenarioConfig.R in case the PR leads to deprecated switches
• [x] All automated model tests pass (FAIL 0 in the output of make test)
• [x] No need to update the changelog CHANGELOG.md