Trailing residual characters

[NathanBaulch]

I occasionally see residual junk after my progress bar in situations when the total width decreases. This can happen when the description shrinks or when the timestamp wraps around (eg 1m59s -> 2m0s), but only when running in non-full width + ANSI code mode.

bar := progressbar.NewOptions64(10, progressbar.OptionSetDescription("lengthy"), progressbar.OptionUseANSICodes(true))
bar.Add(1)
bar.Describe("brief")
bar.Add(1)
// Output:
// brief   1% |                                        |  [0s:0s]s]
//                                                               ^^

It looks like this is a regression introduced in commit df9a997f0a and released in v3.7.3.