Change prefix of p37_specFeDem to pm_specFeDem

[JakobBD]

Purpose of this PR

Was used outside 37

Type of change

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

• Minor change (default scenarios show only small differences)

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)
• The changelog CHANGELOG.md has been updated correctly

[LaviniaBaumstark]

thanks, please, also run make test

[JakobBD]

Have done so over night