Open the composer full screen, as a setting (#401) (#404)

Settings > General > Composing has a new switch, "Open the composer full
screen". With it on, every new composer, whether a new message, reply,
forward or reopened draft, starts maximized. Restore still shrinks it to
a window. A draft put back after an undone or failed send keeps the size
it had. It's off by default, and on a phone, where the composer already
fills the screen, it changes nothing.

One new string, translated in all nine catalogs. The count falling back
to English stays at 16 in every language.

Fixes #401

web/src/locales/pt-BR.ts

@@ -752,6 +752,7 @@ export const catalog: Catalog = {
     "Attachment reminder": "Aviso de anexo",
     "Warn when the message mentions an attachment but none is attached.": "Avisar quando a mensagem mencionar um anexo mas nenhum estiver anexado.",
     "Spell check while typing": "Verificação ortográfica ao digitar",
+    "Open the composer full screen": "Escrever mensagens em tela cheia",
     "Confirm before deleting": "Confirmar antes de excluir",
     "Show message snippets": "Mostrar um trecho das mensagens",
     "Preview the first line of each message in the list.": "Mostrar a primeira linha de cada mensagem na lista.",