Revise make-acme-nn-strus, additional functions, to make :index field of result a map from ids to indexes.

New functions construct map node indexes.
Also renamed some variables a little more rationally.
Rename typo node-seq in make-acme-nn-strus to node-vec
Add add-mapnode-id-to-pair-map, then insert into make-acme-node-vec.

Now make-acme-node-vec makes a vector of mapnode maps that include a
mapnode id as well as entries for each of the mapped LOT items.

add-mapnode-id-to-pair map is defined in terms of
pair-map-to-mapnode-id, which is the composition of
id-pair-to-mapnode-id and pair-map-to-id-pair (which I think were
defined before the previous commit).
Revise make-acme-nn-strus, make-nn-strus to extract ids from nodes rather taking ids as an argument.

In an earlier commit, I made make-acme-nn-strus construct ids for map
nodes, and then passed those ids to make-nn-strus.  But now the mapnode
data maps have an id field, so make-nn-strus can assume that whatever
node info maps are passed in, they will have an id field, and so
make-nn-strus can get the ids from the maps in order to construct the
reverse lookup map from node ids to node indexes.  make-acme-nn-strus
no longer has to deal with ids.