fix: Properly handle UTF-8 characters in ImGUI paths (#2122)

- Fixes a bug where users with special characters in their filenames would not be able to save `dalamudUI.ini`.
- Throw a special warning if `dalamudUI.ini` doesn't exist, as it's not an error case.

Dalamud/Interface/Internal/InterfaceManager.cs

@@ -604,10 +604,17 @@ internal partial class InterfaceManager : IInternalDisposableService
                 if (iniFileInfo.Length > 1200000)
                 {
                     Log.Warning("dalamudUI.ini was over 1mb, deleting");
-                    iniFileInfo.CopyTo(Path.Combine(iniFileInfo.DirectoryName!, $"dalamudUI-{DateTimeOffset.Now.ToUnixTimeSeconds()}.ini"));
+                    iniFileInfo.CopyTo(
+                        Path.Combine(
+                            iniFileInfo.DirectoryName!,
+                            $"dalamudUI-{DateTimeOffset.Now.ToUnixTimeSeconds()}.ini"));
                     iniFileInfo.Delete();
                 }
             }
+            catch (FileNotFoundException)
+            {
+                Log.Warning("dalamudUI.ini did not exist, ImGUI will create a new one.");
+            }
             catch (Exception ex)
             {
                 Log.Error(ex, "Could not delete dalamudUI.ini");

lib/ImGuiScene

@@ -1 +1 @@
-Subproject commit 2f37349ffd778561a1103a650683116c43edc86c
+Subproject commit d5dfde4b39b032430deb46bc61084c18fb54b986