S3 has limits with respect to quantity of parts uploaded

[mmattel]

References: owncloud/ocis#10775 (S3 storage truncated to 250000MB per object without error)

• S3 has a hard limit of 10.000 parts per multipart upload.
  Defined by the S3 provider !!!
• The default part size is 16MB.
• The maximum part size allowed is 5GB (5 * 1024 * 1024 * 1024)

This results in the following:

• With default part size
  max file size: 160GB
• With max part size
  max file size: 50TB --> busts the single object limit of 5TB when using Wasabi S3

Configs:

• Disable multi part upload:
  STORAGE_USERS_S3NG_PUT_OBJECT_CONCURRENT_STREAM_PARTS
• Define part size:
  STORAGE_USERS_S3NG_PUT_OBJECT_PART_SIZE