Say when a session has heart-rate figures but no profile behind them

The heart-rate card hid itself whenever the server resolved no curve.
That is right for a session with no heart rate at all, but wrong for the
common case it also covered: a ride logged from a chest strap through a
provider that reports an average and a peak and nothing in between. The
stats grid shows those two numbers, the card next to them renders
nothing, and the page reads as if it has no heart-rate section rather
than as if the shape behind the numbers is not on record.

Three states now. A curve when there is one; a named absence when the
session carries heart-rate figures without a profile; nothing at all when
nothing was ever measured, since there is no absence to report there and
an empty card would be a shell.

messages/pl.json

@@ -3114,6 +3114,7 @@
         "hrMaxMarker": "Maks. {bpm}",
         "hrRangeValue": "{low} do {high} bpm",
         "hrRangeLabel": "Zakres",
+        "hrNoProfile": "Brak pojedynczych pomiarów tętna dla tej sesji.",
         "sportAverageLabel": "Twoja ostatnia średnia:",
         "zonesTitle": "Strefy wysiłku",
         "zonesCaption": "Jak Twój wysiłek rozłożył się na strefy tętna.",