imgui: update to v1.91.4, make various fixes to overlay (#286)

## Link to GitHub Issue, if one exists
n/a

## Description of change
Update ImGui to `v1.91.4`. We can't update to `v1.91.5` or newer just
yet because impl_spice depends on the old IO model of ImGui which got
removed in `v1.91.5`.

We also can't update the DX9 renderer right now, because at some point
overlay breaks in TDJ (and only in TDJ...)

Enable the new debug logging functionality in ImGui. Add a button in
overlay to toggle debug log window.

Fix some minor bugs spotted by the new ImGui debug log: mismatched API
calls, font loading issues.

## Compiling
👍 

## Testing
In progress.

src/spice2x/overlay/windows/card_manager.cpp

@@ -115,7 +115,6 @@ namespace overlay::windows {
             ImGui::BeginDisabled();
             ImGui::Button("  <No card>  \n  xxxx xxxx xxxx xxxx  ");
             ImGui::EndDisabled();
-            ImGui::PopStyleColor(4);
         }
     }
 

src/spice2x/overlay/windows/config.cpp

@@ -3054,13 +3054,13 @@ namespace overlay::windows {
 
         // workaround for popups triggered by menu, see https://github.com/ocornut/imgui/issues/331
         if (about_popup) {
-            ImGui::OpenPopup("About");
+            ImGui::OpenPopup("About##topbarpopup");
         }
         if (licenses_popup) {
-            ImGui::OpenPopup("Licenses");
+            ImGui::OpenPopup("Licenses##topbarpopup");
         }
         if (shutdown_popup) {
-            ImGui::OpenPopup("System");
+            ImGui::OpenPopup("System##topbarpopup");
         }
 
         // draw popups
@@ -3069,7 +3069,7 @@ namespace overlay::windows {
             bool unused_open = true;
 
             if (ImGui::BeginPopupModal(
-                "System",
+                "System##topbarpopup",
                 &unused_open,
                 ImGuiWindowFlags_AlwaysAutoResize | ImGuiWindowFlags_NoResize)) {
 
@@ -3108,13 +3108,15 @@ namespace overlay::windows {
             
             ImGui::SetNextWindowSize(popup_size, ImGuiCond_Appearing);
             ImGui::SetNextWindowPos(popup_pos, ImGuiCond_Appearing);
-            if (ImGui::BeginPopupModal("About", &unused_open)) {
+            bool unused_open2 = true;
+            if (ImGui::BeginPopupModal("About##topbarpopup", &unused_open2)) {
                 this->build_about();
                 ImGui::EndPopup();
             }
             ImGui::SetNextWindowSize(popup_size, ImGuiCond_Appearing);
             ImGui::SetNextWindowPos(popup_pos, ImGuiCond_Appearing);
-            if (ImGui::BeginPopupModal("Licenses", &unused_open)) {
+            bool unused_open3 = true;
+            if (ImGui::BeginPopupModal("Licenses##topbarpopup", &unused_open3)) {
                 this->build_licenses();
                 ImGui::EndPopup();
             }

src/spice2x/overlay/windows/control.cpp

@@ -178,9 +178,11 @@ namespace overlay::windows {
                     static_cast<int>(ImGui::GetIO().DisplaySize.x),
                     static_cast<int>(ImGui::GetIO().DisplaySize.y));
 
-            // removed for size (along with setting IMGUI_DISABLE_DEMO_WINDOWS
-            // and IMGUI_DISABLE_DEBUG_TOOLS) - saves about 300kb in each
-            // binary
+            if (ImGui::Button("ImGui Debug Log")) {
+                overlay::SHOW_DEBUG_LOG_WINDOW = !overlay::SHOW_DEBUG_LOG_WINDOW;
+            }
+
+            // removed for size (IMGUI_DISABLE_DEMO_WINDOWS)
 
             // metrics button
             // this->metrics_open |= ImGui::Button("Metrics Window");

src/spice2x/overlay/windows/generic_sub.cpp

@@ -206,7 +206,7 @@ namespace overlay::windows {
         bottom_right.x += overlay_content_top_left.x;
         bottom_right.y += overlay_content_top_left.y;
         ImGui::GetBackgroundDrawList()->AddImage(
-            reinterpret_cast<void *>(this->texture),
+            reinterpret_cast<ImTextureID>(this->texture),
             overlay_content_top_left,
             bottom_right);