Show selections as multiscene Vol-E files

## Use Case

Requested by @vianamp. Matheus wants to be able to select a group of cells and quickly switch between them.

Ideally, selecting a group of cells using the existing lasso/box selection tools in CFE, and have them appear as an option in the gallery. When clicked, the Vol-E tab would appear with the selection loaded as a multiscene file.

## Solution

- [ ] Selection groups should appear as an icon in the gallery view.
- [ ] When clicked, the selection group should be loaded as a multiscene file.

## Alternatives

Questions:
- What does the icon look like? Should this be in the gallery view vs. a button you click in the current selection set area?
- How will this interact with custom, per-volume Vol-E parameters (via the Link Path column)? Do we only preserve URL data for multi-channel volumes?
- Are there performance/memory concerns if a user selects hundreds of thousands of volumes?