UX: show a loader when resuming to breakpoint

[davidmarkclements]

sometimes it takes a while resume to the next breakpoint the bottleneck seems to be on the node binary side (we're simply waiting for a break event) so to improve UX we should show some kind of loading symbol.

There are unicode clock symbols (🕐 , 🕒 etc.) for all the hours and half hour points,
let's turn that into an animation and put it somewhere in the ui

Similarly we can extend this to show when a process has finished, where we introduce another icon in place of the timer to show "process finished"