fix: prevent possible memory leak (#1102)

[DiegoCardoso]

CP from #1102

[vaadin-bot]

SonarQube analysis reported 27 issues

• 2 critical
• 8 major
• 16 minor
• 1 info

Top 10 extra issues

Note: The following issues were found on lines that were not modified in the pull request. Because these issues can't be reported as line comments, they are summarized here:

1. Grid.java#L2328: Remove usage of generic wildcard type.
2. Grid.java#L2972: Define a constant instead of duplicating this literal "direction" 4 times.
3. Grid.java#: This file has 1,706 lines, which is greater than 750 authorized. Split it into smaller files.
4. Grid.java#L1887: Call "Optional#isPresent()" before accessing the value.
5. Grid.java#L1888: Either log or rethrow this exception.
6. Grid.java#L1907: Either log or rethrow this exception.
7. Grid.java#L2785: Call "Optional#isPresent()" before accessing the value.
8. Grid.java#L2795: Call "Optional#isPresent()" before accessing the value.
9. Grid.java#L3498: Rename "editor" which hides the field declared at line 1157.
10. Grid.java#L3908: Remove this unused method parameter "event".