Rename ConstantType to BasicType

src/qir/driver/sql/SQLTypeSystem.java

src/qir/types/QIRBasicType.java

src/qir/types/QIRBigNumberType.java

src/qir/types/QIRBooleanType.java

src/qir/types/QIRDoubleType.java

src/qir/types/QIRNumberType.java

src/qir/types/QIRStringType.java