Remove Never-Built and Stub Source Files (#16361)

SysInfoDialog, JumpPointSearch and WebUpdatePlugin are in no CMake list on any platform, and nothing includes ConfigExceptions.hpp, wxinit.h or Utils/Profile.hpp. MultiTaskModel holds only empty namespaces. Also drop the empty GUI_App::system_info() and comments that still mention SysInfoDialog.

src/libslic3r/utils.cpp

@@ -1744,9 +1744,7 @@ std::string format_diameter_to_str(double diameter, int precision)
     return oss.str();
 }
 
-// Returns platform-specific string to be used as log output or parsed in SysInfoDialog.
-// The latter parses the string with (semi)colons as separators, it should look about as
-// "desc1: value1; desc2: value2" or similar (spaces should not matter).
+// Returns platform-specific string to be used as log output.
 std::string log_memory_info(bool ignore_loglevel)
 {
     std::string out;