Finds the asset. The path may either be a simple file name or a relative path (relative to the base resource)
or it may have a prefix, such as "context:" or "classpath:", in which case it is treated as a complete path within the indicated domain. The resulting Resource is then localized (to the provided Locale) and returned as an Asset.
The AssetSource caches its results, so a single Asset instance may be shared among many different components.
@param baseResource base resource for computing relative paths
@param path relative to the base resource
@param locale locale to localize the final resource to
@return the asset