i18n: Add new language from Transifex: bqi (Luri, Bakhtiari)

Transifex says that `mobile.json` is 9.92% translated, and that's
above our 5% threshold for offering it in the UI (see
src/settings/languages.js). So, do that.

See discussion about what names to use in the UI:
  https://chat.zulip.org/#narrow/stream/58-translation/topic/Luri.20.28Bakhtiari.29/near/1554760

Author: chrisbobbe

flow-typed/translations.js

@@ -24,6 +24,10 @@ declare module '../../static/translations/messages_bn.json' {
   declare export default {| [string]: string |};
 }
 
+declare module '../../static/translations/messages_bqi.json' {
+  declare export default {| [string]: string |};
+}
+
 declare module '../../static/translations/messages_ca.json' {
   declare export default {| [string]: string |};
 }

src/i18n/messages.js

@@ -17,6 +17,7 @@ export default {
   be: require('../../static/translations/messages_be.json'),
   bg: require('../../static/translations/messages_bg.json'),
   bn: require('../../static/translations/messages_bn.json'),
+  bqi: require('../../static/translations/messages_bqi.json'),
   ca: require('../../static/translations/messages_ca.json'),
   cy: require('../../static/translations/messages_cy.json'),
   cs: require('../../static/translations/messages_cs.json'),

src/settings/languages.js

@@ -74,6 +74,7 @@ const languages: $ReadOnlyArray<Language> = [
   { tag: 'sr', name: 'Serbian', selfname: 'Српски' },
   { tag: 'uk', name: 'Ukrainian', selfname: 'Українська' },
   { tag: 'ar', name: 'Arabic', selfname: 'العربية' },
+  { tag: 'bqi', name: 'Luri (Bakhtiari)', selfname: 'لوری (بختیاری)' },
   { tag: 'fa', name: 'Persian', selfname: 'فارسی' },
   { tag: 'hi', name: 'Hindi', selfname: 'हिन्दी' },
   { tag: 'ta', name: 'Tamil', selfname: 'தமிழ்' },