LU-16393 o2iblnd: add IBLND_REJECT_EARLY reject reason

LU-16393 o2iblnd: add IBLND_REJECT_EARLY reject reason

Add IBLND_REJECT_EARLY reason for rejecting connection request:
to be used when the device doesn't have any nets added yet or
when there's no active NIs on the net to handle the connection.
These conditions are supposed to occur only when LNI is being
added/initialized, so report at CNETERROR level vs. CERROR.

In lnet, set NI state to ACTIVE only after it has been added
to the list of NIs for the net, so that LND can know that
the NI can be used to accept connections.

Test-parameters: trivial
Signed-off-by: Serguei Smirnov <ssmirnov@whamcloud.com>
Change-Id: I59efb2fdf5d5ceabb6ff23f638ec85da82d57b99
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/51651
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Cyril Bordage <cbordage@whamcloud.com>
Reviewed-by: Frank Sehr <fsehr@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>