function toBlobTagsString(tags) {
    if (tags === undefined) {
        return undefined;
    }
    const tagPairs = [];
    for (const key in tags) {
        if (Object.prototype.hasOwnProperty.call(tags, key)) {
            const value = tags[key];
            tagPairs.push(`${encodeURIComponent(key)}=${encodeURIComponent(value)}`);
        }
    }
    return tagPairs.join("&");
}
Convert Tags to encoded string.

@param tags -