LibPDF: Allow show_text to return errors

Errors can (and do) occur when trying to render text, and so far we've
silently ignored them, making us think that all is well when it isn't.
Letting show_text return errors will allow us to inform the user about
these errors instead of having to hiding them.

Userland/Libraries/LibPDF/Renderer.cpp

@@ -483,7 +483,7 @@ RENDERER_HANDLER(text_next_line)
 RENDERER_HANDLER(text_show_string)
 {
     auto text = MUST(m_document->resolve_to<StringObject>(args[0]))->string();
-    show_text(text);
+    TRY(show_text(text));
     return {};
 }
 
@@ -510,7 +510,7 @@ RENDERER_HANDLER(text_show_string_array)
             auto shift = next_shift / 1000.0f;
             m_text_matrix.translate(-shift * text_state().font_size * text_state().horizontal_scaling, 0.0f);
             auto str = element.get<NonnullRefPtr<Object>>()->cast<StringObject>()->string();
-            show_text(str);
+            TRY(show_text(str));
         }
     }
 
@@ -724,7 +724,7 @@ PDFErrorOr<void> Renderer::set_graphics_state_from_dict(NonnullRefPtr<DictObject
     return {};
 }
 
-void Renderer::show_text(DeprecatedString const& string)
+PDFErrorOr<void> Renderer::show_text(DeprecatedString const& string)
 {
     auto& text_rendering_matrix = calculate_text_rendering_matrix();
 
@@ -748,6 +748,7 @@ void Renderer::show_text(DeprecatedString const& string)
     auto delta_x = glyph_position.x() - original_position.x();
     m_text_rendering_matrix_is_dirty = true;
     m_text_matrix.translate(delta_x / text_rendering_matrix.x_scale(), 0.0f);
+    return {};
 }
 
 PDFErrorOr<NonnullRefPtr<Gfx::Bitmap>> Renderer::load_image(NonnullRefPtr<StreamObject> image)

Userland/Libraries/LibPDF/Renderer.h

@@ -114,7 +114,7 @@ private:
     void begin_path_paint();
     void end_path_paint();
     PDFErrorOr<void> set_graphics_state_from_dict(NonnullRefPtr<DictObject>);
-    void show_text(DeprecatedString const&);
+    PDFErrorOr<void> show_text(DeprecatedString const&);
     PDFErrorOr<NonnullRefPtr<Gfx::Bitmap>> load_image(NonnullRefPtr<StreamObject>);
     PDFErrorOr<void> show_image(NonnullRefPtr<StreamObject>);
     void show_empty_image(int width, int height);