Feature request: easy way to copy links in chat

Currently (keybase 1.7.9 on Linux) to copy a link from chat, one need to select it all and Ctrl+C. This is especially hard in case of long links (multi-line), as the whole message easily get selected.

Proposed solution - right click menu on a link with "Copy URL" action. Similar to many other applications (browsers, gnome-terminal, libreoffice, ...).

Start by locating the chat link-rendering and context-menu entry points in the Keybase client; the issue provides no file or test names. Done means a link exposes a right-click “Copy URL” action without requiring selection, with behavior checked on Linux.

Written by the indexing model from the issue text.