GUI(+CLI) Entire UI freezes during long opperation (e.g. delete).

[fromSmolsoft]

Bug Description
Entire UI layer freezes when intensive operations like delete thousands of dupes is initiated despite CPU / RAM / drive are not fully used.
On Windows it goes into full foggy screen mode on top of mentioned and covers even panel with launcher icons.

Steps to reproduce:

1. scan data worth of 10-100 thousand files and 20 to 100 GB
2. pick few thousands of dupes and press delete or move
3. watch entire app (UI) to freeze for undefined period while CPU / RAM / Drive usage is bellow 30 % OS usage included.

IMHO it looks as if UI and background processes run on same thread, so the UI hangs.
Interestingly when search is initiated, little alert dialog with progress bars doesn't freeze,

System
Basic specs of machines:

• CPU: intel 2, i3, i7;
• RAMs: 3GB, 6GB, 16GB;
• drives: HDD, SSD;
• OS: Lin mint 21.2, Lin mint 21.2, Win11

Czkawka behaves exactly the same on each device.

• Czkawka version:
  • Czkawka GUI +CLI 6.1.0, Windows, was compiled with release mode
  • Czkawka GUI (flatpack) on Linux

[AndroYD84]

Having the same problem. The GUI has been stuck like this for 3 days while doing a mass symlink operation. It takes about 3 days to complete a scan (with cached hashes), so without a import feature as suggested here #1295 there's no way to recover from failure and we lose all progress, it's like walking on egg shells this is incredibly frustrating.