Sum function fails in many use cases

[alsundukov]

Hello @mathiasrw, @gangadhargo!
After the release of v2.2.2 with this commit the Sum formula has stopped working with many user cases:

`
//I changed a little test229.js for testing
...
alasql('insert into RunTotalTestData ([value]) values (1)');
alasql('insert into RunTotalTestData ([value]) values (2)');
...

SELECT SUM(IF(TRUE, a.[value], 0)) FROM RunTotalTestData a // return null

SELECT SUM(a.[value] + ";") FROM RunTotalTestData a // return null
`

Previously, it was possible to sum strings inside the Sum function, use IF, now this does not work.

[gangadhargo]

@alsundukov Thanks for pointing that out.

@mathiasrw what should be the behavior for the above two cases
It seems the condition is wrong inside the sum for the first case the below one working fine.
alasql('SELECT SUM(CASE WHEN TRUE THEN a.[value] ELSE 0 END) FROM RunTotalTestData a') = 3 this is fine.

the second case, shouldn't we treat it as null if the value type is a number with special characters? In this case "3;"?