EID & RFC9758

[olivier-dj]

Address type/range mismatch

https://github.com/DTN-MTP/bp-socket/blob/main/include/bp_socket.h#L57
https://github.com/DTN-MTP/bp-socket/blob/main/bp_socket/af_bp.c#L111

The type is correct (check https://www.rfc-editor.org/rfc/rfc9758.txt), u32.

Add allocator

The ipn scheme allow eid of the form : ipn:[allocator.]node_id.agent_id
We probably do not need to manage the optional: the rfc states that an allocator equal to 0 is equivalent to omitting it in the eid string (i.e. using the default allocator). the allocator can always be present in the struct (and equal to 0 if not present in the eid string)

ref:
The presumption that Node Numbers are allocated by IANA from a
specific registry, unless otherwise specified, is formalized in this
update to the 'ipn' URI scheme by designating IANA as the Default
Allocator and by assigning the Allocator Identifier zero (0) in the
"'ipn' Scheme URI Allocator Identifiers" registry (Section 9.1) to
the Default Allocator. In any case where an encoded ipn URI does not
explicitly include an Allocator Identifier, an implementation MUST
assume that the Node Number has been allocated by the Default
Allocator.

[ricktaylor]

Please add uint32_t allocator_id; to the struct for compliance.

Obviously parser changes need to be made as well.