Add Crop Mode to Image Resizer

### Description of the new feature / enhancement

Image Resizer is great to batch-resize images. More often than not, there is a need to bulk-crop (e.g. screenshots) in order to get rid of taskbars, secondary monitors (that have been screenshot as well) etc.

# Basics
2 checkboxes, 4 text fields
1. CB x symmetrical
2. CB y symmetrical
3. crop left
4. crop top
5. crop right (= left, if CB x Symm is checked)
6. crop bottom (= top, if CB y Symm is checked)

# Further Ideas
- introduce preview (show thumbnail preview, and overlay crop margins, maybe also support to skip through the image batch selected)
- switch between units
- absolute (Px)
- relative (%)
- switch between outside & inside mode
- support height and width instead of crop margins
- set pivot point (fixed for all, but in the future maybe add support for a list/file read-in as well or let this be configured inside the tool)

### Scenario when this would be used?

Bulk-crop into mutliple images at once. This might be great for image collections, step-by-step guides and image dataset preparation.

### Supporting information

_No response_

No files, tests, or code entry points are named. First locate the Image Resizer entry point and establish which basic crop controls are in scope; done means the agreed crop behavior works for batches and its behavior is covered by tests.

Written by the indexing model from the issue text.