run less more robustly; don't add --quit-at-eof

[simonmichael]

This adds more robust handling of various less and pager failure mode. Generally when anything goes wrong, it should always fall back to printing the output unpaged.

Based on feedback from chat, I have removed --quit-at-eof from the options that hledger adds to LESS when using less as pager. It meant that when you scrolled to the bottom of long output, you would often end up exiting less by accident, so you couldn't scroll back up. Now when less is invoked (because output is longer than the window), you'll always see its end of output indicator at the bottom and you'll always have to press q to exit.

Of course you can override this default by setting your preferred less options in HLEDGER_LESS (or by setting PAGER to something else or by using --pager=no).

Related: #2544

[simonmichael]

This is in today's https://github.com/simonmichael/hledger/releases/tag/testlatest binaries, all testing including on old environments is welcome.