`gh stack submit` does not respect org-wide PR template

My organisation has an org-wide PR template, just as the one described here: https://github.com/orgs/community/discussions/183776. We used to have these templates in each repo, but they were all the same and repetitve, so we decided to define them in one place. We'd rather not go back to per-repo template.

Unfortunately, `gh stack submit` does not seem to respect them. User has two options with this command:
* By default it opens CLI dialog to enter PR's title and description. It doesn't use the org template
* `--auto` creates PR with some pre-populated footer and nothing else. Again no template is used.

The command supports repo-wide templates, thanks to https://github.com/github/gh-stack/pull/77, but this PR does not seem to take org-wide templates into account.

Inizia tracciando il punto di ingresso `gh stack submit` e i relativi percorsi della finestra di dialogo predefinita e di `--auto`, usando github/gh-stack pull request #77 come contesto per i template a livello di repository. Riproduci entrambe le modalità con un template di PR a livello di organizzazione, quindi verifica che la pull request risultante includa quel template senza perdere il footer esistente.

Scritto dal modello di indicizzazione a partire dal testo della issue.