EZP-31545: Filtered empty idString

[ViniTou]

Question	Answer
Tickets	https://jira.ez.no/browse/EZP-31545
Bug fix?	yes
New feature?	no
BC breaks?	no
Tests pass?	yes
Doc needed?	no
License	GPL-2.0

As it was reported as "pgsql only", it turned out it is just because

SELECT COUNT(*) FROM ezcontentobject_tree t INNER JOIN ezcontentobject c ON t.contentobject_id = c.id INNER JOIN ezcontentobject_version v ON c.id = v.contentobject_id WHERE ((1 = 1) AND (t.node_id IN (?))) AND (c.status = ?) AND (v.status = ?) AND (t.depth <> ?) AND ((c.language_mask & ?) > ?)' with params ["NaN", 1, 1, 0, 3, 0]

is valid query for mysql.

Checklist:

• Coding standards ($ composer fix-cs)
• Ready for Code Review

[micszo]

The fix is incomplete.

Steps:

1. Create new policy and select limitation while creating it. [OK]
2. Create new policy without a limitation.
3. Edit that policy and select limitation. [NOK]

Bcoz Chrome :|

[micszo]

QA Approved on master with pgsql and mysql.