* Fix copy/paste of empty newlines again
Fixes: https://github.com/go-gitea/gitea/issues/19331
Regressed by: https://github.com/go-gitea/gitea/pull/18270
Needed to do another newline addition to the Chroma output HTML to get
copy/paste work again. The previous replacement conditions are probably
obsolete, but as I'm not 100% sure, I opted to keep them.
Specifically, the Chroma HTML change mentioned in
https://github.com/go-gitea/gitea/pull/18270#issuecomment-1013350246
broke our previous newline replacement for such empty lines.
Also included are a few changes to make the test more pleasant to work
with.
* run go mod tidy
* add util.Dedent
* copy in the code
Co-authored-by: techknowlogick <techknowlogick@gitea.io>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: Lauris BH <lauris@nix.lv>
silverwind