feat(Order/WellFoundedOn): wfon.mapsTo and sdff_singleton

[pechersky]

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[github-actions]

PR summary de3ca0d8c3

Import changes for modified files

No significant changes to the import graph

Import changes for all files

Files	Import difference

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Declarations diff

+ WellFoundedOn.mapsTo
+ WellFoundedOn.sdiff_singleton
+ wellFoundedOn_sdiff_singleton

You can run this locally as follows

## summary with just the declaration names:
./scripts/declarations_diff.sh <optional_commit>

## more verbose report:
./scripts/declarations_diff.sh long <optional_commit>

The doc-module for script/declarations_diff.sh contains some details about this script.