[GITEA] Add download URL for executable files

- Consider executable files as a valid case when returning a downloadURL
for them. They are just regular files with the difference being the
executable permission bit being set.
- Not integration testing as it's not possible without adding adjusting
the existing repositories to have a executable file.
- Resolves https://codeberg.org/forgejo/forgejo/issues/1825

(cherry picked from commit ca32891d54)
(cherry picked from commit 72c9df8e45)
(cherry picked from commit 0eae22d429)
(cherry picked from commit d37d0773bc)
(cherry picked from commit de4532a967)
(cherry picked from commit f5b41300a8)
(cherry picked from commit d3be0480b7)
(cherry picked from commit c72307fd3b)
(cherry picked from commit 71db593057)

services/repository/files/content.go

@@ -220,7 +220,7 @@ func GetContents(ctx context.Context, repo *repo_model.Repository, treePath, ref
 		}
 	}
 	// Handle links
-	if entry.IsRegular() || entry.IsLink() {
+	if entry.IsRegular() || entry.IsLink() || entry.IsExecutable() {
 		downloadURL, err := url.Parse(repo.HTMLURL() + "/raw/" + url.PathEscape(string(refType)) + "/" + util.PathEscapeSegments(ref) + "/" + util.PathEscapeSegments(treePath))
 		if err != nil {
 			return nil, err