Refactor "change file" API (#34855)

Follow up the "editor" refactor, use the same approach to simplify code,
and fix some docs & comments

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Signed-off-by: wxiaoguang <wxiaoguang@gmail.com>
Co-authored-by: delvh <dev.lh@web.de>

services/repository/files/patch.go

@@ -44,7 +44,6 @@ type ApplyDiffPatchOptions struct {
 	NewBranch    string
 	Message      string
 	Content      string
-	SHA          string
 	Author       *IdentityOptions
 	Committer    *IdentityOptions
 	Dates        *CommitDateOptions