Reduce usage of db.DefaultContext (#27073)

Part of #27065

This reduces the usage of `db.DefaultContext`. I think I've got enough
files for the first PR. When this is merged, I will continue working on
this.

Considering how many files this PR affect, I hope it won't take to long
to merge, so I don't end up in the merge conflict hell.

---------

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

routers/web/repo/view.go

@@ -1091,7 +1091,7 @@ func Forks(ctx *context.Context) {
 	pager := context.NewPagination(ctx.Repo.Repository.NumForks, setting.ItemsPerPage, page, 5)
 	ctx.Data["Page"] = pager
 
-	forks, err := repo_model.GetForks(ctx.Repo.Repository, db.ListOptions{
+	forks, err := repo_model.GetForks(ctx, ctx.Repo.Repository, db.ListOptions{
 		Page:     pager.Paginater.Current(),
 		PageSize: setting.ItemsPerPage,
 	})