[Feature Request]: Support writing Datetime metadata Fields

[henri98]

I'm digitizing old negatives from my childhood. Once digitized, I want to import them into Immich, so it would be useful to have accurate date and time metadata for the photos in order to place them correctly on Immich's timeline. Also the age feature relies on the date time information within the picture.

I'am thinking of the following flow:

1. Choose the date time when the photo roll was developed, apply it on all photo's of the roll.
2. More accurate entry of the date time per photo.

[davidkingsman]

That's also what's holding me back from using NegPy.
A way to set the DateTimeOriginal EXIF field would be great!