fix(showcase): fixes ReactiveSearch React and Vue showcase demos

[siddharthlatest]

Fixes ReactiveSearch React and Vue showcase demos

• Changes the index to use the demo cluster index
• Fixes Maps API key
• Updates to the latest ReactiveSearch / ReactiveMaps versions

Page(s) affected:

• https://docs.appbase.io/docs/reactivesearch/v3/overview/Showcase/
• https://docs.appbase.io/docs/reactivesearch/vue/overview/Showcase/

[vercel[bot]]

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