Dedicated page for adding data

[AlonaNadler]

We are rethinking the Kibana home page and working on some mockups (see #25734)
While currently most of the items in Kibana home have their dedicated place in the UI (e.g., Canvas, APM Discover, etc...), you can get to the Add Data only from the home page.

Also, we now have multiple ways to add data, but these are in different areas of Kibana
If we decide to pursue the design in the issue linked above for Kibana home, I suggest we have a dedicated add data page which will help users understand what are the ways to add data (or what to do when you already have data in Elasticsearch, and you just started to use Kibana- index pattern often confuse new users)
Add Data page can include:

• Beats tutorials
• ML File uploader
• Sample data
• Navigation to create an index pattern

The goal is not to move the features but to create easier navigation and help users understand what are their options when it comes to adding data

these are a few examples how other solutions in the market surface adding data in their UI

cc: @ryankeairns @alexfrancoeur

[elasticmachine]

Pinging @elastic/kibana-app

[snide]

I am closing this issue in favor of #36708, which the observability team is currently building. I've given @hbharding some awareness that he'll need to consider CSV uploads there.