[TablePlugin] Table cells merging POC

[dimaanj]

Summary

What had been done

• Merge
• Unmerge
• Resize with merged cells
• Handy cells selection
• Inserting and removal rows and columns

Things to consider

• Performance for huge tables
• insertTableRow and insertTableColumn calls keep state of colIndex, rowIndex, colSpan, rowSpan for all cells. So running them multiple times synchronously won't lead to a problems.
• ⚠️ deleteColumn, deleteRow, mergeCells, unmergeCells will modify cells structure and won't update colIndex, rowIndex, colSpan, rowSpan for affected cells. It's ok, since valid indexes and spans will be assigned in useTableCellElementState hook on each render, but invoking that functions multiple times synchronously won't work.
• Inserting subtables might be flaky with merged cells if you can spot it
• Tiny issues with resize, if you can find them

Functionality

merging.mp4

Pasting from Word

pasting-from-word.mp4

Pasting from other sites

pasting-from-sites.mp4

[changeset-bot]

⚠️ No Changeset found

Latest commit: 06315fd

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

This PR includes no changesets

When changesets are added to this PR, you'll see the packages that this PR includes changesets for and the associated semver types

Click here to learn what changesets are, and how to add one.

Click here if you're a maintainer who wants to add a changeset to this PR

[vercel]

The latest updates on your projects. Learn more about Vercel for Git ↗︎

Name	Status	Preview	Comments	Updated (UTC)
plate	❌ Failed (Inspect)			Oct 3, 2023 4:37pm

[WcaleNieWolny]

Your code does not build

[dimaanj]

Your code does not build

Will check it

[zbeyens]

Continues in #2666