[Media Converter] Add selective metadata preservation for image conversions

## Extension https://www.raycast.com/leandro.maia/media-converter ## OS Version macOS 27.0 ## Description Media Converter currently offers one **Strip metadata (EXIF, GPS, tags)** checkbox. When enabled, it removes all metadata; when disabled, metadata preservation is left to the underlying conversion behavior. Please add an explicit metadata policy for image conversions, especially HEIC to JPEG: - Preserve all supported metadata - Remove location/GPS metadata only - Remove all metadata Removing location data should preserve other useful fields when the output format supports them, such as capture date, camera details, orientation, copyright, and descriptive metadata. This should be available per conversion and as a default preference. ## Who will benefit from this feature? People who want to share converted photos without revealing their location while retaining useful non-location metadata. ## Anything else? The current all-or-nothing metadata option was added in https://github.com/raycast/extensions/pull/27390. JPEG quality controls already exist, so this request is only about explicit metadata preservation.