Properly support S3 structs

[sbernauer]

When implementing support for S3 in the operators out there we took some shortcuts like ignoring accessStyle and tls settings for now. We need to honor them and not just silently ignore them.

What needs to be done is described in stackabletech/issues#226

[fhennig]

accessStyle has already been implemented by Sebastian, now tls is missing.

Setting https for the druid.s3.protocol should enable HTTPS/TLS for connecting to s3 (docs).

A custom CA cert for the s3 instance looks a bit tricky, the s3 docs don't mention anything like that. On the TLS docs site there's a section Custom Certificate Checks. An extension allows to supply custom certificates to be checked, but I am unsure whether these are also used for the s3 connection, or just for inter-process communication.

Edit: I've asked on the Druid Google user group: https://groups.google.com/g/druid-user/c/P8sSKp2QJbc

[fhennig]

On the google group a user replied:

Currently, I don't know a way to add the custom CA certificate for S3 communication. A workaround could be to add the CA certificate to the java Keystore which is under /lib/security/carcerts.

Since we control the container, I think this might be a good solution for us