Convert locale files from ini to json format (#35489)

Migrate from the current INI format to JSON for translations. JSON is
widely supported, including by platforms such as Crowdin and Weblate.

templates/home.tmpl

@@ -1,5 +1,5 @@
 {{template "base/head" .}}
-<div role="main" aria-label="{{if .IsSigned}}{{ctx.Locale.Tr "dashboard"}}{{else}}{{ctx.Locale.Tr "home"}}{{end}}" class="page-content home">
+<div role="main" aria-label="{{if .IsSigned}}{{ctx.Locale.Tr "dashboard"}}{{else}}{{ctx.Locale.Tr "home_title"}}{{end}}" class="page-content home">
 	<div class="tw-mb-8 tw-px-8">
 		<div class="center">
 			<img class="logo" width="220" height="220" src="{{AssetUrlPrefix}}/img/logo.svg" alt="{{ctx.Locale.Tr "logo"}}">