Add duration formatter about fmt HOT 6 CLOSED

Seems relevant:

• serokell/o-clock#19

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There's diffF already but I agree that we should have something like this.

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Though obviously baking-in 8 hour days won't be good

from fmt.

Maybe we can indeed use the o-clock idea with series. I think that instead of type-level lists we can just have a list of predefined (Builder, Int) pairs. @chshersh what do you think?

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@neongreen Well, since there's o-clock I don't actually need durationF formatter anymore. seriesF is enough to me. I won't use this formatter on something that doesn't represent time. And if I need time I probably will use o-clock. seriesF is already a good reason for me to use package like o-clock. Though, o-clock probably should have Buildable instance but at this moment it's not clear for me which exact Buildable should it use...

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It looks like we don't need this — please feel free to reopen if you disagree.

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