During closing a livechat session an error occur :
_get_visitor_leave_message() got an unexpected keyword argument 'speaking_with'
Because argument 'speaking_with' is pass in this method https://github.com/odoo/odoo/blob/14.0/addons/im_livechat/models/mail_channel.py#L182, it should be operator.

closes odoo/odoo#70630

Signed-off-by: Thibault Delavallee (tde) <tde@openerp.com>

Make translation works for "Website Visitor" that was appearing when a
logged-out user open a livechat session.

note: list comprehension has to be removed since translation only search
language in direct calling method closure.

opw-2504461

closes odoo/odoo#70135

X-original-commit: 7e0cf9679ee86e1b3e8094606fd815ffe46eb3c1
Signed-off-by: Nicolas Lempereur (nle) <nle@odoo.com>

This commit fixes two issues encountered during the visitor lifecycle.

1. When a visitor arrives on the website on a non tracked page, a
website.visitor is not created yet, but the visitor can still start a livechat
session. When navigating to a tracked page, a website.visitor is created but the
lifechat session already started is not recovered and the discussion is lost at
visitor's side. This commit links the already started livechat session to the
newly created visitor to ensure that the conversation can still continue
normally.

2. When a visitor logs in, his attributed visitor is linked to the partner. But
there can be only one visitor per partner. If there was already a visitor linked
to the partner, the later visitor's livechat session are updated with the
partner and the visitor is then deleted. But the visitor's livechat sessions are
not linked to the main partner visitor. So when looking at all the session the
partner had, we can only see the main visitor's livechat session.
This commit copy the livechat session of that later visitor to the main partner
visitor to ensure keeping the complete livechat history for each partner.

Task ID: 2460892

closes odoo/odoo#66179

Signed-off-by: Thibault Delavallee (tde) <tde@openerp.com>