fix: fix default objectstore class and remove autocreate

[xoxys]

• replace objectstore class OCA\\ObjectStore\\S3 by OCA\Files_Primary_S3\S3Storage
• remove unsupported bucket autocreate option

[phil-davis]

@xoxys can you write something about why this change is needed?

[xoxys]

What information is missing?

The old objectstore class was deprecated a long time ago and was not working anymore. The current one is following our docs https://doc.owncloud.com/server/latest/admin_manual/configuration/files/external_storage/s3_compatible_object_storage_as_primary.html#amazon-s3

The autocreate option does not exist anymore (and for this reason does not work). After internal discussions, this was never intended to work, so lets remove it.

[phil-davis]

"The old objectstore class was deprecated a long time ago and was not working anymore"

"The autocreate option does not exist anymore"

That's good to know - answers my "why" thoughts, thanks.

[xoxys]

Sorry it that was unclear, I thought the information from the pr message were enough :) Thanks for your review