WRQ-31515: Fixed `Scroller`, `VirtualList`, and `VirtualGridList` to set prop value to default when `undefined` is passed for the prop value

Checklist

[x] I have read and understand the contribution guide
[x] A CHANGELOG entry is included
[ ] At least one test case is included for this feature or bug fix
[x] Documentation was added or is not needed
[ ] This is an API breaking change

Issue Resolved / Feature Added

In https://github.com/enactjs/enact/pull/3238, we removed defaultProps and implemented this feature manually. After this implementation, if undefined is passed for a prop value, the prop value remains undefined. However, defaultProps(https://legacy.reactjs.org/docs/typechecking-with-proptypes.html#default-prop-values) sets prop value to default value when undefined value is passed for the prop.

Resolution

Fix Scroller, VirtualList and VirtualGridList to set prop value to default value when undefined is passed for the prop value

Additional Considerations

I checked React's defaultProps for falsy values(null, undefined, false, NaN, 0, -0, "") and found that it sets the prop value to its default value only when undefined is passed.

And it seems that React's defaultProps only checked undefined.

Links

WRQ-31515

Comments

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 82.52%. Comparing base (ef8be8e) to head (cdbdc77). Report is 2 commits behind head on release/4.9.x.develop.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## release/4.9.x.develop #3265 +/- ## ========================================================= + Coverage 82.51% 82.52% +0.01% ========================================================= Files 157 157 Lines 7245 7251 +6 Branches 1919 1921 +2 ========================================================= + Hits 5978 5984 +6 Misses 995 995 Partials 272 272 ```

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enactjs / enact