[Mime] Add TemplatedEmail::locale() to set the locale for the email rendering

[alexander-schranz]

Q	A
Branch?	6.4
Bug fix?	no
New feature?	yes
Deprecations?	no
Tickets	Fix #...
License	MIT
Doc PR	symfony/symfony-docs#...

Add LocaleSwitcher to TemplatedEmail BodyRenderer. Currently it is not possible to render a twig template or a converter in a specific locale context.

It is common to send the email in the language of the receiver.

Usage

$email = (new TemplatedEmail())
    ->to('fabien@symfony.com')
    ->from('helene@symfony.com')
    ->subject('Hallo!')
    ->locale('de')
    ->textTemplate('email.txt.twig')
    ->htmlTemplate('email.html.twig')
    ->context($context)
;

[nicolas-grekas]

LGTM.
Please just add a line in the changelog of the bridge.

[nicolas-grekas]

ah, can you please check tests?

[nicolas-grekas]

tests still :)

[fabpot]

Thank you @alexander-schranz.