nominateCandidates = (moduleSpecifier, searchSuffixes) => {
  // Collate candidate locations for the moduleSpecifier,
  // to support Node.js conventions and similar.
  const candidates = [moduleSpecifier];
  for (const candidateSuffix of searchSuffixes) {
    candidates.push(`${moduleSpecifier}${candidateSuffix}`);
  }
  return candidates;
}
Expands a module specifier into a list of potential candidates based on
`searchSuffixes`.

@param {string} moduleSpecifier Module specifier
@param {string[]} searchSuffixes Suffixes to search if the unmodified
specifier is not found
@returns {string[]} A list of potential candidates (including
`moduleSpecifier` itself)