Fix issues with Datasets preview

The CKAN Datastore extension provides a database that allows us to upload dataset resources, that can the be automatically previewed and automatically provides a Data API for search, filter and updating datasets etc.

On auditing the current datasets, there were few issues
1. Only datasets upload via the API and explicitly making a call to `resource_create`,e.g sensors.Africa datasets were automatically uploaded to the datastore and had preview + Data API as below
2. Datasets created manually via the `create datasets` form do not automatically upload to the datastore and therefore not available for previews. We are currently using the legacy [Datapusher ](https://github.com/ckan/datapusher), however CKAN recommends upgrading to either of the plugins [here](https://docs.ckan.org/en/2.10/maintaining/datastore.html#id7) for automatic datasets upload
3. We had a Cloudflare WAF rule to manage bot requests to the `/datasets` endpoint (temporarily disabled), however this is called when previewing. With Cloudflare raises a 403, so we need a workaround