Remove leading spaces from message log zone strings (#4945)

The "from …" fragments built by getFromStr() carried a leading space so
the sentence templates could concatenate them directly (%2%3). That blank
is invisible on Transifex and most translations dropped it, merging the
card name and the zone phrase in the log (#4943).

Drop the blank from the tr() strings and add the separator in code where
the fragment is built. The space is only prepended when the fragment is
non-empty, so messages that put the zone in the card name instead — "the
top card of their library." — keep their punctuation tight.

The templates stay at %2%3, since %3 is empty on those paths.

cockatrice/src/game_graphics/log/message_log_widget.cpp

@@ -120,6 +120,11 @@ MessageLogWidget::getFromStr(CardZoneLogic *zone, QString cardName, int position
     if (!cardNameContainsStartZone) {
         cardName.clear();
     }
+    // The separator space is added here rather than stored in the tr() string so
+    // translators never have to preserve an invisible leading blank.
+    if (!fromStr.isEmpty()) {
+        fromStr.prepend(' ');
+    }
     return {cardName, fromStr};
 }