File picker does not have option for large thumbnails or grid view

## What Happened
There is no obvious option to view large thumbnails. Currently, it appears that the file picker only has a List View with tiny thumbnails. This makes it extremely difficult, if not impossible, to pick images visually. Even 5.1.7 Hera's file picker had slightly larger thumbnails.

## Expected Behavior

The File picker should have an option to list files in Grid View (multiple sizes available) or List View, similar to how the Files interface provides a Grid or List View.

EDIT: The 6.0 File picker does display a large thumbnail to the right of the list, but this is to report **the lack of a real grid view.**
A user should not need to click though multiple files to see if the thumbnail is the correct one.

## Steps to Reproduce

Use any app that opens a File Picker.

### Logs

## Platform Information

OS: elementary OS 6 Odin x86_64
Kernel: 5.11.0-27-generic
Packages: 1699 (dpkg), 20 (flatpak)
Shell: bash 5.0.17
Resolution: 3840x2160
DE: Pantheon
WM: Mutter(Gala)
Theme: io.elementary.stylesheet.blueberry [GTK3]
Icons: elementary [GTK3]
Terminal: io.elementary.t
CPU: Intel Xeon W3680 (12) @ 3.326GHz
GPU: NVIDIA GeForce GT 1030
Memory: 1370MiB / 24047MiB