Delta IO Connector

### Motivation

Hello.

I have been using Apache Druid on and off for some time. Most recently, I used it as the base for a Lakehouse architecture I designed. I have been deploying it alone via K8S vanilla style, without any operators or hosted clouds etc with good success.
However, since I am a big fan of the open source data layer created by databricks: [delta.io](http://delta.io/) , I ended up doing tedious movements of delta -> raw parquet -> load to druid .

presto has recently created a [delta.io](http://delta.io/) adapter to link delta files directly, this is making me consider to use a presto cluster instead (would scale decently enough with current data load I have to work with).
However, is there anyone who has faced this issue and solved it in a “nice” way, or are there any plans to add a delta connector similar to what presto has done?

Here is a reference to what presto has added: https://prestodb.io/blog/2022/03/15/native-delta-lake-connector-for-presto
And a video: https://www.youtube.com/watch?v=JrXGkqpl7xk (fast forward to `21:40`).

### Proposed changes

Implement delta.io connector to load in into apache druid.

### Rationale

Currently it is very tedious, and a bit inefficient when you are working with delta.io as your underlaying layer, to then have another service extracting version `N` of delta to load into raw parquet, to make it accessible to `apache druid`.

### Operational impact

It should be done in a way so it does not impact backwards compatibility.

Review Apache Druid's existing connector architecture and the linked Presto Delta Lake connector reference; the issue names no Druid files or tests. Establish the supported Delta Lake versions, read/version semantics, and backward-compatibility requirements before defining the work. Done would mean an agreed scope and a functioning Delta Lake connector integrated without breaking existing behavior.

Written by the indexing model from the issue text.