Belle-sip : Add a function to compare Route headers

Anthony Gauchy
2023-11-29T15:44:57Z

(cherry picked from commit 4350e919def0e067048b1b769df448fe13c472bb)

See https://gitlab.linphone.org/BC/public/flexisip/-/merge_requests/1060

Linked : https://gitlab.linphone.org/BC/public/belle-sip/-/merge_requests/336 ; https://gitlab.linphone.org/BC/public/linphone-sdk/-/merge_requests/3935 ; https://gitlab.linphone.org/BC/public/flexisip/-/merge_requests/1061