res_pjsip: chatty verbose messages

There are a lot of verbose messages about Endpoint and Contact status
changes if there are many dynamic endpoints.
The patch sets verbose level 2 for Endpoint status changes
and verbose level 3 for Contact status changes.

ASTERISK-26055 #close

Change-Id: Ie64e261ddbbc41bfff0f0190241152cc123fe6d7