Add open as base64

[E3V3A]

Hi, apparently the Google (and others) sources git repository doesn't allow you to directly download the source code shown on their web pages. See for example UiccController.java. There are no buttons to let you download or see this code in raw form. The only hope is by adding the extension ?format=TEXT to generate the base64 format of the same code.

So it would be extremely useful for a huge number of people if we could use your plugin to view also base64 encoded pages. I.e. Open in browser as: Decoded Base64 text.

[spasche]

I've never encountered a lot of base64 encoded content in responses, but I wouldn't be against a pull request that offers the option I guess.

[E3V3A]

Apparently there is a built-in JS function that does this automatically: atob(encodedString);. However, it may not work for binary blobs. Instead it has been suggested to use THIS or THIS. I don't know how to write this into your plug-in, but might be a simple matter if you already know how it works.