test: improve tests execution time

[datamweb]

Description This PR tries to speed up the execution of tests by setting a value of $hashCost = 4 for the test environment. More Info see #916

Checklist:

• [x] Securely signed commits
• [ ] Component(s) with PHPDoc blocks, only if necessary or adds value
• [ ] Unit testing, with >80% coverage
• [x] User guide updated
• [x] Conforms to style guide