Fix/import perf filtervalue

Optimize value access from product by attribute code.
Bug fix: [no]
Feature addition: [no]
Backwards compatibility break: [yes]
Unit test passes: [yes]
Specs passes: [N.A.]
Replaced unit test classes removed: [N.A.]
Behat scenario passes: [yes]
Checkstyle issues: [no]
ChangeLog updated: [yes]
Documentation PR: [N.A.]
Fixes the following jira: N.A.