Reduce set of example queries from the specification, pending future …

…improvements (#357)

optimade/validator/data/filters.txt

@@ -1,41 +1,14 @@
-_exmpl1_bandgap<2.0 OR _exmpl2_bandgap<2.5
-NOT ( chemical_formula_hill = "Al" AND chemical_formula_anonymous = "A" OR chemical_formula_anonymous = "H2O" AND NOT chemical_formula_hill = "Ti" )
+NOT ( chemical_formula_anonymous = "A" OR chemical_formula_anonymous = "H2O" )
 nelements > 3
-chemical_formula_hill = "H2O" AND chemical_formula_anonymous != "AB"
-_exmpl_aax <= +.1e8 OR nelements >= 10 AND NOT ( _exmpl_x != "Some string" OR NOT _exmpl_a = 7)
-_exmpl_spacegroup="P2"
-_exmpl_cell_volume<100.0
-_exmpl_bandgap > 5.0 AND _exmpl_molecular_weight < 350
-_exmpl_melting_point<300 AND nelements=4 AND elements="Si,O2"
-_exmpl_some_string_property = 42
-5 < _exmpl_a
-identifier CONTAINS x
-identifier STARTS WITH x
-identifier ENDS WITH x
 chemical_formula_anonymous CONTAINS "C2" AND chemical_formula_anonymous STARTS WITH "A2"
 chemical_formula_anonymous STARTS "B2" AND chemical_formula_anonymous ENDS WITH "D2"
-list HAS value
-list HAS ALL values
-list HAS ANY values
-list LENGTH value
-NOT list HAS inverse
-calculations.id HAS "calc-id-96"
-authors.lastname HAS "Schmit"
-identifier IS UNKNOWN
-NOT identifier IS KNOWN
-chemical_formula_hill IS KNOWN AND NOT chemical_formula_anonymous IS UNKNOWN
-NOT a > b OR c = 100 AND f = "C2 H6"
-(NOT (a > b)) OR ( (c = 100) AND (f = "C2 H6") )
-a >= 0 AND NOT b < c OR c = 0
-((a >= 0) AND (NOT (b < c))) OR (c = 0)
 elements HAS ALL "Si", "Al", "O"
 elements HAS ALL "Si", "Al", "O" AND elements LENGTH 3
 nelements=4
 nelements>=2 AND nelements<=7
 chemical_formula_descriptive="(H2O)2 Na"
 chemical_formula_descriptive CONTAINS "H2O"
 chemical_formula_reduced="H2NaO"
-chemical_formula_hill="H2O2"
 chemical_formula_anonymous="A2B"
 nsites=4
 nsites>=2 AND nsites<=7