IEMailTemplate::setLanguage() sets the lang and dir attributes of the
email, mirrors the layout for right-to-left languages and becomes the
default language of the footer. Every email sent by server now passes
the language it is written in.
Assisted-by: ClaudeCode:claude-opus-5-5
Signed-off-by: John Molakvoæ <14975046+skjnldsv@users.noreply.github.com>