Export an image

### User Story Description

As a user, I want to be able to export an image from the viewer.

### Acceptance Criteria

Start a VISOR session. Load a dataset. Use the API call to export an image. An image is generated on disk. Now, change the model visualization (parts visibility, mesh, color by variable, ....). Use the same API to export an image. The image shows the current state of VISOR.

### Additional Links

_No response_

### Requires new or update to third party ? If "yes" add the name(s) and the version(s) of the Third Party Software.

No

### Name and Version for Third Parties

_No response_

啟動一個 VISOR 工作階段，載入資料集，並找出用於 viewer 操作的現有 API 入口點。在變更零件可見性、網格或依變數設定的色彩之前和之後各匯出一張影像；當兩張影像都寫入磁碟，且第二張反映目前的視覺化狀態時，即表示完成。

由索引模型根據 Issue 內容生成。