Have an easier way to open article content in webview

Original issue title: Swipe right on the Reading Page to open article content in webview

1. Environment

• Device: [Pixel 7 Pro]
• OS: [Android 14]
• APP: [0.10.1]

2. Describe the feature request

If I’m reading an article I should be able to swipe to the right to open the article content in Webview. Currently if I’ve read an article to the end and than subsequently decided I want to view the full webpage, usually because I want to view the article comments, I have to scroll all the way back to the top and click on the title.

This is unnecessarily cumbersome, my proposed solution would be to mimic what Reeder for iOS/Mac OS does which is a simple swipe to the right. They also use the swipe up and down for going between articles, so this UX has been established before.

Im aware of the discussion in #144 and agree that a left and right swipe should be used to move ‘laterally’ as per the material guidelines and as such should not be used for going between different articles. A right swipe to open the page in webview makes sense as the webview is ‘peer content’, it also does not currently have an easy way to access it from the bottom of a article.

No source files or tests are named. Start by reviewing the reading-page navigation and discussion in #144, then trace how the article title currently opens the WebView; done means a right swipe from article content reliably opens the full webpage without breaking article-to-article navigation.