Field order can break query parsing

[jonasagx]

The following query can be parsed:

FILTER AND ( _field < "now-30d", _num_something = 1, EXISTS(field) ) FROM user

While this one failed:

FILTER AND (_num_something = 1, EXISTS(field), _field < "now-30d" ) FROM user

With:
parse_filterql.go:439: could not parse: parse error: Un recognized input Got Token{ Type:"Error" Line:1 Col:45 Q: Pos:45} near: , _field < "now-30d