Add concepts tests + some fixes

python/ql/test/library-tests/frameworks/airspeed/ConceptsTest.expected

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+testFailures
+failures

python/ql/test/library-tests/frameworks/airspeed/ConceptsTest.ql

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+import python
+import experimental.meta.ConceptsTest

python/ql/test/library-tests/frameworks/airspeed/template_test.py

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+from airspeed import Template
+
+def test():
+    return Template("abc") # $ templateConstruction="abc"