Add option to preserve metadata

[wildyaboku]

Overview

Adds an option to the GUI for preserving metadata on upscaled images and videos, with three different levels:

• Disabled: No metadata will be copied to output images/videos
• Basic: Only basic metadata (mostly informational like title, description, author, tags) will be copied
• Full: Copies all metadata including unsafe image-altering data (like color profiles), embedded thumbnails, and more

For this to work, exiftool.exe must be installed on the system, or available in the same directory as QualityScaler.exe. Binaries for exiftool can be found here: https://exiftool.org/install.html

• Note: if the downloaded file is called exiftool(-k).exe, it must be renamed to exiftool.exe first.
• If anyone is using this app from another OS, they can install exiftool globally using their package manager, it'll work.

As for the GUI, I squished an option in where I could, just for experimentation. I'll leave the final design to you, if you decide to merge these changes.

Generally, it only takes a fraction of a second to copy metadata, but I recommend "disabled" as the default option because there are important caveats:

• Different file formats support different metadata tags, so data is lost when converting between different formats
• This effectively makes a full copy of the final file, which means 2x the disk writes
• Some formats (like PNG) can be very slow to write metadata when the output image is extra large

Testing

Here's an image suitable for testing:

If you download this image and open it in Windows Explorer, you should see some metadata under the details tab:

Upscaling this image should yield different results depending on whether the metadata level is set to Disabled or Basic.