Improve quality of automatic annotations

The 'Annotate Automatically' algorithm of 'Add Switch Matrix Coordinates' tool produces less-than-ideal connections for some layouts, especially when ergonomic layouts with column splay.

See following groups:

**very good**:

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**decent**:

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**bad**:

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Start by locating the implementation and entry point for the “Annotate Automatically” algorithm in the “Add Switch Matrix Coordinates” tool. Reproduce the layouts shown in the issue, especially ergonomic layouts with column splay, and compare the generated connections with the examples. Done means the automatic annotations produce consistently improved connections for the reported layout groups.

Written by the indexing model from the issue text.