Documentation, factorization, and small fixes

src/qir/driver/sql/SQLTypeSystem.java

src/qir/types/QIRAnyType.java

src/qir/types/QIRBigNumberType.java

src/qir/types/QIRBooleanType.java

src/qir/types/QIRBottomType.java

src/qir/types/QIRConstantType.java

src/qir/types/QIRDoubleType.java

src/qir/types/QIRFunctionType.java

src/qir/types/QIRListType.java

src/qir/types/QIRNumberType.java

src/qir/types/QIRRecordType.java

src/qir/types/QIRSomeType.java

src/qir/types/QIRStringType.java

src/qir/types/QIRType.java

src/qir/typing/QIRSpecificTypeSystem.java