Datatable: restore prop propagation behaviour

[alexzherdev]

#2993 introduced a slight regression around propagating table props to cells.

Additional description

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CONTRIBUTOR checklist (do not remove)

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• npm run lint:fix has been run and linting passes.
• Mocha, Jest (Storyshots), and components/component-docs.json CI tests pass (npm test).
• Tests have been added for new props to prevent regressions in the future. See readme.
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REVIEWER checklist (do not remove)

• CircleCI tests pass. This includes linting, Mocha, Jest, Storyshots, and components/component-docs.json tests.
• Tests have been added for new props to prevent regressions in the future. See readme.
• Review the appropriate Storybook stories. Open http://localhost:9001/.
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• Review tests are passing in the browser. Open http://localhost:8001/.
• Review markup conforms to SLDS by looking at DOM snapshot strings.

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[interactivellama]

@alexzherdev One of the things I've noticed is that we don't look to be taking advantage of your great improvements in our examples and therefore, other teams are not likely using this memoize strategy. Could you update at least one example/story (if not all them), so that bugs like this can be caught more easily?