message: Uniqueify include string proposals
diff: @@ -2905,7 +2905,7 @@ bool QueryDbMainLoop(
  }
  // Build include strings.
  - std::vector<std::string> include_insert_strings;
  + std::unordered_set<std::string> include_insert_strings;
  include_insert_strings.reserve(include_absolute_paths.size());
  for (const std::string& path : include_absolute_paths) {
  @@ -2913,9 +2913,9 @@ bool QueryDbMainLoop(
  if (!item)
  continue;
  if (item->textEdit)
  - include_insert_strings.push_back(item->textEdit->newText);
  + include_insert_strings.insert(item->textEdit->newText);
  else if (!item->insertText.empty())
  - include_insert_strings.push_back(item->insertText);
  + include_insert_strings.insert(item->insertText);
  else
  assert(false && "unable to determine insert string for include completion item");
  }
  @@ -2939,7 +2939,7 @@ bool QueryDbMainLoop(
  // Setup metadata and send to client.
  if (include_insert_strings.size() == 1)
  - command.title = "Insert " + include_insert_strings[0];
  + command.title = "Insert " + *include_insert_strings.begin();
  else
  command.title = "Pick one of " + std::to_string(include_insert_strings.size()) + " includes to insert";
  command.command = "cquery._insertInclude";
  