Bluetooth: Mesh: Fix provisioner provisioning

Correct format errors, such as oob action 2-octers
should use 0x%04x, and action in prov capalilities pdu
big-ending. When every call `bt_mesh_auth_method_set<*>`
should also clear auth value, otherwise will case confirm
failed.

Provisioner role expect peer public key should be sent
immediately, instead of requiring ACK. After all, ACK may
be lost, and the other device’s public key will be sent
over, and provisioning procedure will be failed..

This is a resubmission of PR (#30086)

Signed-off-by: Lingao Meng <menglingao@xiaomi.com>