Steepen wind offshore ramp-up

[lecfab]

Purpose of this PR

In this issue, we see that wind-offshore near-term development is too weak.
This PR implements a temporary solution (option 1 in the issue): the upper-bound on offshore follows a fast s-curve instead of a slower sort-of-linear increase.

Next step will be to define offshore as an independent technology with its own historical data and bounds,

Type of change

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

• Bug fix
• Refactoring
• New feature
• Minor change (default scenarios show only small differences)
• Fundamental change
• This change requires a documentation update

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

Further information (optional):

• Test runs are here: /p/tmp/fabricel/offshoreRemind
• Comparison of results (what changes by this PR?):

Before (AMT) / after:

[LaviniaBaumstark]

why is this PR still open?