OpenDAL capability should represent the maximum service capacity rather than its current configuration

OpenDAL uses `Capability` to represent the operations supported by services. Historically, we have provided separate configurations for users to customize services, such as `batch_max_operations` and `disable_stat_with_override`.

This might be confusing for features that users can enable or disable, such as bucket versioning. When users set `enable_versioning`, they might think they are enabling versioning on the bucket itself, but in reality, it only toggles a flag in OpenDAL.

Perhaps we should offer users a way to adjust the capability themselves, rather than attempting to create configurations for every field.

Start by reviewing the Capability concept and the existing configuration options named in the issue, including batch_max_operations, disable_stat_with_override, and enable_versioning. Define what it means for capability to represent maximum service capacity and what user-facing adjustment API would be needed; done requires an agreed design that avoids configuration flags being mistaken for service-side settings.

Written by the indexing model from the issue text.