add missing methods imploementations for `src/Repositories/H5PRepository.php`

[qunabu]

there are unimplemented method in src/Repositories/H5PRepository.php

example

/**
     * Load config for libraries.
     *
     * @param array $libraries
     *
     * @return array
     */
    public function getLibraryConfig($libraries = null)
    {
    }