Support exporting rendered entity fields using View Modes [#3608125]

Problem/Motivation

The Views Data Export module is excellent for exporting raw field values from Views displays. However, there is currently no straightforward way to export data using an entity's configured View Mode rendering. The module is designed to export data from Views displays and their selected fields, but exported content is typically based on field output rather than entity view mode rendering

Many sites have display logic configured in View Modes that includes:

Field formatters
Computed fields
Custom preprocess logic
Layout Builder configurations
Contributed formatter output
Custom business logic applied during entity rendering

When exporting data, site builders must often recreate this logic using additional Views fields or custom code.

Proposed resolution

Add support for exporting rendered entity output using a selected View Mode.
Possible implementation:

Add an option in the Data Export display configuration to select a View Mode.
Render each entity using the selected View Mode before export.
Allow the rendered output to be exported as a dedicated column.
Support Content entities, Taxonomy terms, Users, and other entity types supported by Views.

Use Cases

Exporting content exactly as displayed on the website.
Creating feeds for external systems.
Exporting formatted HTML content.
Reusing View Mode configurations without duplicating display logic.
Supporting Layout Builder–based exports.

Expected Workflow

Create a View.
Add a Data Export display.
Enable Render entity using View Mode.
Select a View Mode (e.g., Full, Teaser, Export).
Export data with the rendered output included.

Benefits

Reduces custom development.
Reuses existing Drupal display configuration.
Keeps export output consistent with site presentation.
Improves integration with Layout Builder and formatter-based content.

Additional Notes

A dedicated Export view mode could be created by site builders and used specifically for export purposes, allowing full control over exported output without affecting website displays.