Reindexing has unexpected results

[ugm2]

• Reindexing with keyword search pipelines doesn't work, the first indexed documents prevail

• Reindexing in any pipeline doesn't clear index so the documents will just add-up

• Fix keyword search indexing

• Add clear index option in the UI

[ugm2]

The issue on keyword search, which uses Tfidf, depends on this other issue in Haystack: deepset-ai/haystack#1634

I will check the fix on keyword search indexing since it doesn't depend on me.

A workaround for this would be to implement the feature add clear index so we are always working with a clean index

[ugm2]

The workaround didn't work for keyword search, so it will only work after refreshing the page

[ugm2]

It seems I've been able to solve the issue by not indexing documents with the same ID.

Also, now clear index is implemented