Fix style of product type attributes empty table

[orzechdev]

I want to merge this change because... it displays just no attributes found message without table header when there are no attributes to display in the table.

PR intended to be tested with API branch:

Screenshots

Pull Request Checklist

1. All visible strings are translated with proper context.
2. All data-formatting is locale-aware (dates, numbers, and so on).
3. Translated strings are extracted.
4. Number of API calls is optimized.
5. The changes are tested.
6. Data-test are added for new elements.
7. Type definitions are up to date.
8. Changes are mentioned in the changelog.

Test environment config

API_URI=https://master.staging.saleor.rocks/graphql/

[patrys]

Task linked: SALEOR-1247 Broken table on product type view

[krzysztofwolski]

LGTM

[krzysztofwolski]

Storybook seems to be in good condition too https://fix-product-type-attributes-empty-table.dashboard.saleor.rocks/storybook/index.html?path=/story/views-product-types-product-type-details--no-attributes

[orzechdev]

passed to QA

[mlamperski]

Tested positive on deployed environment and checked storybook