Add a tooltip explaining what a locked account is (#9403)

* create a title tooltip explaining what a locked account is

* improve phrasing

* minor phrasing fix to unify default and english

app/javascript/mastodon/features/account/components/header.js

@@ -16,6 +16,7 @@ const messages = defineMessages({
   unblock: { id: 'account.unblock', defaultMessage: 'Unblock @{name}' },
   edit_profile: { id: 'account.edit_profile', defaultMessage: 'Edit profile' },
   linkVerifiedOn: { id: 'account.link_verified_on', defaultMessage: 'Ownership of this link was checked on {date}' },
+  account_locked: { id: 'account.locked_info', defaultMessage: 'This account privacy status is set to locked. The owner manually reviews who can follow them.' },
 });
 
 const dateFormatOptions = {
@@ -148,7 +149,7 @@ class Header extends ImmutablePureComponent {
     }
 
     if (account.get('locked')) {
-      lockedIcon = <i className='fa fa-lock' />;
+      lockedIcon = <i className='fa fa-lock' title={intl.formatMessage(messages.account_locked)} />;
     }
 
     const content         = { __html: account.get('note_emojified') };

app/javascript/mastodon/locales/en.json

@@ -17,6 +17,7 @@
   "account.follows_you": "Follows you",
   "account.hide_reblogs": "Hide boosts from @{name}",
   "account.link_verified_on": "Ownership of this link was checked on {date}",
+  "account.locked_info": "This account privacy status is set to locked. The owner manually reviews who can follow them.",
   "account.media": "Media",
   "account.mention": "Mention @{name}",
   "account.moved_to": "{name} has moved to:",

app/javascript/mastodon/locales/pl.json

@@ -17,6 +17,7 @@
   "account.follows_you": "Śledzi Cię",
   "account.hide_reblogs": "Ukryj podbicia od @{name}",
   "account.link_verified_on": "Własność tego odnośnika została potwierdzona {date}",
+  "account.locked_info": "To konto jest prywatne. Właściciel ręcznie wybiera kto może go śledzić.",
   "account.media": "Zawartość multimedialna",
   "account.mention": "Wspomnij o @{name}",
   "account.moved_to": "{name} przeniósł(-osła) się do:",