applet: Change bold up/down arrow characters to regular arrow characters

The current arrows U+2B07 & U+2B06 are thick versions (and also used for emoji). Change to the normal arrow characters U+2193 & U+2191 which complement the alphanumeric text better, and perhaps are more semantically correct in this context wrt how fonts expect characters to be used.

Before (Inter font)	After (Inter font)

I don't fully understand the emoji behavior -- it seems Inter's up arrow is more emoji-like? It at least doesn't match the down arrow visually.