feat: add language switcher (#1337)

## Description

Web changes:

- Enabled i18n for web
- Add option to change language in command menu
- Add option to change language in menu-switcher

Web and marketing changes:

- Stop setting 'en' preference into cookie if the user's language is not
supported
- Dropped middleware changes
- Rotated cookie from 'i18n' to 'language'

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

- **New Features**
- Introduced a language switcher in the footer for improved language
selection.
	- Added dynamic language change functionality in the command menu.
- Implemented a dropdown menu item for quick access to the language
switcher.

- **Bug Fixes**
- Resolved issues related to language change notifications and state
management.

- **Translations**
- Added new translation entries for improved language support, including
"Search languages..." in English and German.
	- Updated existing translations to enhance clarity and accuracy.

- **Chores**
	- Simplified internationalization handling in middleware.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

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Co-authored-by: github-actions <github-actions@documenso.com>

packages/ui/components/common/language-switcher-dialog.tsx

@@ -0,0 +1,57 @@
+import { msg } from '@lingui/macro';
+import { useLingui } from '@lingui/react';
+import { CheckIcon } from 'lucide-react';
+
+import { SUPPORTED_LANGUAGES } from '@documenso/lib/constants/i18n';
+import { switchI18NLanguage } from '@documenso/lib/server-only/i18n/switch-i18n-language';
+import { dynamicActivate } from '@documenso/lib/utils/i18n';
+import { cn } from '@documenso/ui/lib/utils';
+import {
+  CommandDialog,
+  CommandGroup,
+  CommandInput,
+  CommandItem,
+  CommandList,
+} from '@documenso/ui/primitives/command';
+
+type LanguageSwitcherDialogProps = {
+  open: boolean;
+  setOpen: (_open: boolean) => void;
+};
+
+export const LanguageSwitcherDialog = ({ open, setOpen }: LanguageSwitcherDialogProps) => {
+  const { i18n, _ } = useLingui();
+
+  const setLanguage = async (lang: string) => {
+    setOpen(false);
+
+    await dynamicActivate(i18n, lang);
+    await switchI18NLanguage(lang);
+  };
+
+  return (
+    <CommandDialog open={open} onOpenChange={setOpen}>
+      <CommandInput placeholder={_(msg`Search languages...`)} />
+
+      <CommandList>
+        <CommandGroup>
+          {Object.values(SUPPORTED_LANGUAGES).map((language) => (
+            <CommandItem
+              key={language.short}
+              value={language.full}
+              onSelect={async () => setLanguage(language.short)}
+            >
+              <CheckIcon
+                className={cn(
+                  'mr-2 h-4 w-4',
+                  i18n.locale === language.short ? 'opacity-100' : 'opacity-0',
+                )}
+              />
+              {SUPPORTED_LANGUAGES[language.short].full}
+            </CommandItem>
+          ))}
+        </CommandGroup>
+      </CommandList>
+    </CommandDialog>
+  );
+};