Generated gitdescribe file on all unix platforms so the test reports upload job will get the right version

-Improved comments of report history generation
-Simplified creation of directories
-Noted limitations
-Fixed test reports history gathering when there are already some for the current branch
-Unified way to get SDK version in order to avoid delta between git describe in docker container and the git describe of the machine in charge of uploads

This lead to avoid receving push notification for my own message.

- Fixes long filenames deletion issue by batch gitlab-runner
- Prepares future updates as gitlab batch runner is deprecated

Implement ephemeral messages notify callbacks

That prevented from building the SDK with other version of libxerces
than 3.1, which may happen while building Flexisip since it uses
the libxerces provided by the system.

Fix bad chat room when creating a call. Previously, on the call of getOrCreateBasicChatRoom, a chat room with the same peer address was returned without takking account of the local address that could come from multi-accounts.

Fix sending authentification by fixing unmatching proxy on linphone_core_lookup_proxy_by_identity. Default proxy could be different from the URI we want that lead to unexpected behaviour on wrong assertion. Update subscription on remote conference list event if it was the same as the cleared proxy config.