Handle base64 encoded image rendering

[MewX]

Example review reply:

包含分卷列表：第三卷 瑠璃骑士<code><pre>{"UID":"<UUID>","aid":"3067","pathname":"/novel/3/3067/index.htm","ImgLocation":null,"ImgLocationBase64":"UEsDBAoAAAAIAF2wt1hi9rJclgAAAJQDAAALAAAASW1nTG9jYXRpb26l0rEKAjEMBuB3yXxI0rRN6+zi7iZSDpXzBKXoIYL47h7i1C7Brn/4IOHP9gWP8QBLIPbMETq45/66Xs3J5jml/anP0/GWaB6Ml+Gbk4Ro3eKcB3h3f3LfxqWNhzYem7hDFcfElktKSmqNLalRUhFTUlZSIsTSWq3lWK3slNag+NJ6rWVfFSRaG1x1b1CXi1W7v7/afQBQSwECFAAKAAAACABdsLdYYvayXJYAAACUAwAACwAAAAAAAAAAAAAAAAAAAAAASW1nTG9jYXRpb25QSwUGAAAAAAEAAQA5AAAAvwAAAAAA"}</pre></code>