Support Multiple Curations on Topic Pages

[rebeccamcginn]

Resolves https://jira.dev.bbc.co.uk/browse/WSTEAMA-117

Overall change: Support multiple curations on the Topic page

Code changes:

• Remove BFF backward-compatible code from getInitialData; Now only accessing data.curations
• Rename promos to curations, render each curation
• Updated test fixtures

TO DO:

• promoEntities is mapping over the curations right now, not mapping over each summary item. This needs updated so that we create a data object for each summary item on the page.

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• [ ] I have assigned myself to this PR and the corresponding issues
• [ ] I have added the cross-team label to this PR if it requires visibility across World Service teams
• [ ] I have assigned this PR to the Simorgh project
• [ ] (BBC contributors only) This PR follows the repository use guidelines

Testing:

• [ ] Automated (jest and/or cypress) tests added (for new features) or updated (for existing features)
• [ ] If necessary, I have run the local E2E non-smoke tests relevant to my changes (CYPRESS_APP_ENV=local CYPRESS_SMOKE=false yarn test:e2e:interactive)
• [ ] This PR requires manual testing