Revert "Add '{title}' and '{layer}' functionality to the Export dialog (fix aseprite/aseprite#3363)"

Fix crash reported on v1.2.36/v1.3-beta17, ctx->activeDocument() can
be nullptr.

This reverts commit 1f5e4cfc4f to fix #3431

src/app/commands/cmd_save_file.cpp

@@ -23,7 +23,6 @@
 #include "app/file/gif_format.h"
 #include "app/file/png_format.h"
 #include "app/file_selector.h"
-#include "app/filename_formatter.h"
 #include "app/i18n/strings.h"
 #include "app/job.h"
 #include "app/modules/gui.h"
@@ -391,11 +390,7 @@ void SaveFileCopyAsCommand::onExecute(Context* context)
     if (!result)
       return;
 
-    FilenameInfo fnInfo;
-    fnInfo
-      .filename(context->activeDocument()->name())
-      .layerName(win.layersValue());
-    outputFilename = filename_formatter(win.outputFilenameValue(), fnInfo);
+    outputFilename = win.outputFilenameValue();
 
     if (askOverwrite &&
         base::is_file(outputFilename)) {

src/app/doc_exporter.cpp

@@ -689,11 +689,6 @@ Doc* DocExporter::exportSheet(Context* ctx, base::task_token& token)
   // Save the image files.
   if (!m_textureFilename.empty()) {
     DX_TRACE("DocExporter::exportSheet", m_textureFilename);
-    // filename_formatter usage to include {title} key word on CLI.
-    FilenameInfo fnInfo;
-    fnInfo.filename(ctx->activeDocument()->name());
-    m_textureFilename = filename_formatter(m_textureFilename.c_str(), fnInfo);
-
     textureDocument->setFilename(m_textureFilename.c_str());
     int ret = save_document(ctx, textureDocument.get());
     if (ret == 0)