New feature: File download support

[EnotShow]

Now if the database value is the file path and the file exists it will be shown as a downloadable file

Before: After:

Changes affect templates: deteils.html, list.html

[agn-7]

This PR solves the #701 issue.

[EnotShow]

I decided that the user wants to have not only a download method but a reading method too. Now, besides the download method, there's an additional option to open files directly in a browser.

Additionally, I've addressed a security concern from the previous version. Instead of using file paths in the URL, which is insecure.

Now the result looks like:

Please let me know when you check my MR. I'm will grateful for the feedback