feat: upload folder includes which all files

[r0kk]

Description

• Users are able to select the folder upon all files in folder and subfolders will be selected for upload.
• Fixes [REQUEST] How to select many files at a time. #589

Type of change

• New features (non-breaking change).

Checklist

• I have performed a self-review of my code.
• I have added thorough tests if it is a core feature.
• There is a reference to the original bug report and related work.
• I have commented on my code, particularly in hard-to-understand areas.
• The feature is well documented.

Screenshot of the added functionality

[r0kk]

Hi, I know it is a bit hacky solution, but it works. I know you were making some changes so this code doesn't work in entirety (it works if you comment out the _process_single_file. I know you were making some changes related to the path management and renaming that is why function valid_files gets file path, that doesn't exist. I hope you will be able to make quick fix, because I am a bit under time pressure, but still find it useful functionality.