Add optimization direction or range to `ColumnAnnotation`

[zhu0619]

Context

45 reminded the fact the "optimization direction" or "optimal value range" is important to benchmark for generative model, such as molecular generation and optimization.

Description

Currently, this optimization direction and thresholds are handled in user_attributes.

Acceptance Criteria

• The relevant attributes direction,threshold or opt_interval are added to the ColumnAnnotation class.

---

This is a low priority task, maybe for V1?

[cwognum]

Interesting! I haven't thought a lot about generative benchmarks yet, but it seems to me this would be so different we would end up introducing a new BenchmarkSpecification subclass (see e.g. also #5) that would maybe be better suited to store this information.