Summary:
Adds a `data-grist-col-ref` attribute to the copied HTML, then uses that when pasting to look up the source column and retrieve info about it. Copies the info into the target column if:
- The document is the same (the docId hash matches)
- The source column still exists and has the same type as when copied
- The source type isn't Text, because in that case it's nice if type guessing still happens
- The target column is empty, meaning it has type Any (we check earlier that it's not a formula column)
The info copied is the type, widgetOptions, and reference column settings (visible and display columns) but not conditional formatting.
The changes are mostly in a function `parsePasteForView` which is based on `BaseView._parsePasteForView` but ported to TypeScript in a new file `BaseView2.ts`.
Added a useraction `MaybeCopyDisplayFormula` exposing an existing Python function `maybe_copy_display_formula` because the target column needs a slightly different display formula.
Test Plan: Added a new nbrowser test file and fixture doc.
Reviewers: cyprien
Reviewed By: cyprien
Subscribers: jarek, dsagal
Differential Revision: https://phab.getgrist.com/D3344
