If the Redis connection was lost, we might have missed a notification of an account being created/updated/deleted, so we drop all current accounts and re-create a fresh set from DB.
We were already fetching all accounts again on reconnection, but we were ignoring them because we already had corresponding accounts in our pool.
This commit makes sure we use the latest values from db.
b2bua: sip-bridge: account-pool: Better reflect that a full load may happen again
tests: b2bua: sip-bridge: account-pool: Test account reload on Redis re-subscribe
tests: fix: StaticAccountLoader can now return accounts multiple times
Closes FLEXISIP-476