query: fix some double quote parsing/serialization issues.
- fixes
"\"a b\""parsed to {simple query with value: '"a b"'} serialized to"\"a b\""
/bug #20190603-E76ED6 https://nexedijs.erp5.net/#/bug_module/20190603-E76ED6
"\"a b\""
parsed to {simple query with value: '"a b"'}
serialized to "\"a b\""
/bug #20190603-E76ED6 https://nexedijs.erp5.net/#/bug_module/20190603-E76ED6