ADD DepthAnythingV2 Metric Depth

DepthAnythingV2にMetric Depth版を追加して、オプションで切り替えられるようにする。
https://github.com/DepthAnything/Depth-Anything-V2/blob/main/metric_depth/README.md
標準のモデルは相対深度だが、これは絶対深度で、ロボットなどに応用が期待できる。

Start with the linked DepthAnythingV2 metric-depth README to understand the model and its required options, then locate the existing DepthAnythingV2 integration in this repository. Done means the Metric Depth model is included and can be selected optionally, producing absolute rather than relative depth; the issue does not name a file or test to run.

Scritto dal modello di indicizzazione a partire dal testo della issue.