Don't translate 'Premium/Premium+'

- Forgot that we've concluded to not translate 'Premium/Premium+' and keep that as a product name. This is the same as competitors.
- For other instances of "Premium" in a longer string, we'll just have to communicate with translators to not translate it.
- Remove a few old strings.

static/app-strings.json

@@ -1030,10 +1030,6 @@
   "%complete% / %total% videos transferred": "%complete% / %total% videos transferred",
   "Confirm": "Confirm",
   "Reward validation pending": "Reward validation pending",
-  "Checkout": "Checkout",
-  "Your cart contains 1 item.": "Your cart contains 1 item.",
-  "lbry.tv Premium - 1 month": "lbry.tv Premium - 1 month",
-  "We will refund no questions asked within 30 days.": "We will refund no questions asked within 30 days.",
   "Buy": "Buy",
   "buy": "buy",
   "Country": "Country",
@@ -2226,9 +2222,7 @@
   "early access": "early access",
   "site-wide badge": "site-wide badge",
   "Available Memberships": "Available Memberships",
-  "Premium": "Premium",
   "Badge on profile, livestreaming, automatic rewards confirmation, and early access to new features": "Badge on profile, livestreaming, automatic rewards confirmation, and early access to new features",
-  "Premium+": "Premium+",
   "Badge on profile, livestreaming, automatic rewards confirmation, early access to new features, and no ads": "Badge on profile, livestreaming, automatic rewards confirmation, early access to new features, and no ads",
   "Join via %interval% membership": "Join via %interval% membership",
   "Interval": "Interval",

ui/component/common/premium-badge.jsx

@@ -26,9 +26,9 @@ export default function PremiumBadge(props: Props) {
   return (
     <BadgeWrapper linkPage={linkPage}>
       {badgeToShow === 'silver' ? (
-        <CommentBadge label={__('Premium')} icon={ICONS.PREMIUM} {...badgeProps} />
+        <CommentBadge label={'Premium'} icon={ICONS.PREMIUM} {...badgeProps} />
       ) : (
-        badgeToShow === 'gold' && <CommentBadge label={__('Premium+')} icon={ICONS.PREMIUM_PLUS} {...badgeProps} />
+        badgeToShow === 'gold' && <CommentBadge label={'Premium+'} icon={ICONS.PREMIUM_PLUS} {...badgeProps} />
       )}
     </BadgeWrapper>
   );