[Feature] Add/edit comment in EXIF and subsequent show it

[StanTody]

Checklist

• I made sure that there are no existing issues - open or closed - to which I could contribute my information.
• I made sure that there are no existing discussions - open or closed - to which I could contribute my information.
• I have read the FAQs inside the app (Menu -> About -> FAQs) and my problem isn't listed.
• I have taken the time to fill in all the required details. I understand that the bug report will be dismissed otherwise.
• This issue contains only one feature request.
• I have read and understood the contribution guidelines.
• I optionally donated to support the Fossify mission.

Feature description

I suggest Gallery to have a function to add/edit a comment to EXIF info of one or more images, and this comment (optionally) to be shown over image or next to it.

Why do you want this feature?

It's very handy to have a description for photos - for reminding the moment or for additional notes for the subject (in which shop is the article in photo, for example).

Additional information

May be used EXIF tag Description or tag User comment.