fix(dash): urlencode special parameters like `:` in query (#12811)
In macOS, using queries such as `dash php:enum` does not open Dash.app,
possibly due to colon character being interpreted as a port.
URL-encoding the parameter (: -> %3A) makes this work again.
Fixes https://discord.com/channels/642496866407284746/809850042575093760/1308076125456437300