samples: Bluetooth: Minor improvements for broadcast audio sink

Increases some of the timeouts so that when using this sample
against other interactive devices (such as a phone or the
Zephyr audio shell), then it's easier to do it in time.

Also updates a few of the printks and ensures that we are not
doing name filtering when we have been requested to sync to
a specific broadcast source by a broadcast assistant.

The test for the sample has also been modified to have a longer
timeout to accomodate for the new semaphore timeout values.

Signed-off-by: Emil Gydesen <emil.gydesen@nordicsemi.no>