Add loopback design files and update project configurations

- Created a new loopback design file (loopback.bda) with nodes and edges defined in GraphML format.
- Added a new Vivado project file for loopback (loopback.xpr) with updated configurations.
- Introduced a new testbench for image convolution (img_conv_tb.vhd) in the simulation sources.
- Updated the main project file (lab2.xpr) to reflect changes in source files and top module for simulation.
- Removed obsolete project files (pak_depak.xpr.zip) and updated paths for existing source files.

.gitignore

@@ -51,7 +51,6 @@
 *.cache/
 *.hw/
 *.gen/
-*.srcs/
 .hwdbg/
 *.ip_user_files/
 .webtalk/