System context menu for URLs

**The problem**
Sometimes I would like to perform actions to URLs on a post/comment (e.g. share, open in a specific browser, etc). On the PWA, long pressing on a link pops the system context menu (seen in #441) which allows us to choose an action. On the Android app, we get a useless pop-up as seen in #1123.

This also applies to "Touch Friendly Links" when enabled.

#1123 mentioned this being "a native iOS thing". Unfortunately, (1) this is on Android, and (2) it's definitely not native behaviour.

**Desired solution**
System context menu on URL long-press.

**Alternatives considered**
Works on the PWA