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/ui/datefield.tsx

@@ -239,7 +239,7 @@ export function DateField({ value, onChange, className, disabled, required, id,
         <CalIcon size={15} />
       </button>
       {anchor && (
-        <Popover anchor={anchor} onClose={() => { setAnchor(null); inputRef.current?.focus(); }} role="dialog" className="dp-pop" closeOnClick={false} ariaLabel="Choose a date">
+        <Popover anchor={anchor} onClose={() => { setAnchor(null); inputRef.current?.focus(); }} role="dialog" className="dp-pop" closeOnClick={false} ariaLabel={translate("Choose a date")}>
           <CalendarGrid
             selected={selected}
             onClose={() => { setAnchor(null); inputRef.current?.focus(); }}
@@ -335,7 +335,7 @@ export function DateTimeField({ value, onChange, className, disabled, required,
         <span className="dp-open" aria-hidden="true"><Clock size={15} /></span>
       </span>
       {anchor && (
-        <Popover anchor={anchor} onClose={close} role="dialog" className="dp-pop dp-pop-wide" closeOnClick={false} ariaLabel="Choose a date and time">
+        <Popover anchor={anchor} onClose={close} role="dialog" className="dp-pop dp-pop-wide" closeOnClick={false} ariaLabel={translate("Choose a date and time")}>
           <div className="dp-split">
             <CalendarGrid
               selected={valid}