Allow for preprocessing or pretty printing

[salva]

I find myself repeatedly combining bat with a pretty printer, as in: jq . file.json|bat -l JSON

IMO, it would be very handy to have the preprocessing/pretty printing integrated into bat, so that one could just run it like bat -P file.json.

(And I know about prettybat from the bat-extras repository, but still, I think having the feature natively supported would be much better)

[sharkdp]

Potential solution: #2203

[eth-p]

Another potential solution: #2444.

Support for LESSOPEN/LESSCLOSE is not yet included in release bilds by default, but if/when it is, it would be possible to use it to run pretty printers as an input preprocessor.