sparql: SPARQL 1.1 UNION/MINUS/BIND/VALUES/aggregation + 'a' shorthand + loud rejection of unsupported forms (v0.4.5)

The evaluator silently mis-parsed UNION/MINUS/BIND/VALUES/SERVICE/GRAPH into empty results.
Adds real support for UNION, MINUS (antijoin), BIND (arith+CONCAT/STR), VALUES, and
COUNT/SUM/AVG/MIN/MAX with GROUP BY; 'a' now expands to rdf:type; and unsupported query
forms throw an explicit error instead of returning silently-wrong empties. 182 tests green.

Author: mdheller

package.json

@@ -1,7 +1,7 @@
 {
   "name": "@socioprophet/hellgraph",
-  "version": "0.4.3",
-  "description": "HellGraph \u2014 TypeScript OpenCog-compatible AtomSpace metagraph engine (PLN, ECAN, pattern matcher, SPARQL/Gremlin, SHACL, Atomese, StorageNode federation). Polyglot sibling of the Rust hellgraph crate.",
+  "version": "0.4.5",
+  "description": "HellGraph — TypeScript OpenCog-compatible AtomSpace metagraph engine (PLN, ECAN, pattern matcher, SPARQL/Gremlin, SHACL, Atomese, StorageNode federation). Polyglot sibling of the Rust hellgraph crate.",
   "license": "UNLICENSED",
   "type": "commonjs",
   "main": "ts/dist/index.js",