Fix#33358, fix#21970
This adds a step in the `GitDiffForRender` that does syntax highlighting for the
entire file and then only references lines from that syntax highlighted
code. This allows things like multi-line comments to be syntax
highlighted correctly.
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Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>
This module is merged from https://github.com/go-gitea/git which is a Go module to access Git through shell commands. Now it's a part of gitea's main repository for easier pull request.