Check component props for untranslated literals, and fail on a finding

i18n-literals checked title, aria-label, placeholder and alt on elements,
but not the same English passed to a component, so a MenuItem label or a
Popover ariaLabel written as a literal went through. It also excused a
literal that happened to be a catalogue key. That exemption is meant for
English held in a constant and translated where it renders, and a literal
written straight into a JSX attribute has no such render site. No
component passes its props through t(). And neither half of i18n:check
was run with --check, so a finding printed and the script still exited 0.

Component props are checked now, a key no longer excuses a literal in an
attribute, and both scripts run with --check. That found 28 strings
rendering English in every language: 19 already had keys and are wrapped,
and 9 are new keys in all nine catalogues. The contact editor's Save and
Saving… buttons are wrapped as well, on the same line.

web/src/locales/nl.ts

@@ -1183,6 +1183,15 @@ export const catalog: Catalog = {
     "Resize panes": "Vensterdelen verslepen",
     "Resize message list": "Grootte van de berichtenlijst wijzigen",
     "Resize sidebar": "Grootte van de zijbalk wijzigen",
+    "Hide from list": "Verbergen in de lijst",
+    "Show in list": "Tonen in de lijst",
+    "Stop trusting sender images": "Afbeeldingen van afzender niet meer vertrouwen",
+    "Always show images from sender": "Afbeeldingen van afzender altijd tonen",
+    "Collapse all": "Alles samenvouwen",
+    "Expand all": "Alles uitvouwen",
+    "Send now instead": "Toch nu verzenden",
+    "Switch to plain text": "Overschakelen naar platte tekst",
+    "Switch to rich text": "Overschakelen naar opgemaakte tekst",
     "QR code": "QR-code",
     "Draft discarded": "Concept weggegooid",
     "Draft saved": "Concept opgeslagen",