In order to be able to flag the livechat as inactive when the visitor left the
conversation, livechat_active field is moved to im_livechat module, as it is
not linked to website_visitor.
This commit is also a preparation for next one, which will implement the close
conversation right after the first click on x button in livechat window (at
visitor side). We needed the livechat_active flag to be available without
website installed.
Task ID: 2120210
PR #39939
David Beguin
20a7ae2657