Fix: filter_var usage

[iRedds]

Description
When using the flag parameter in the filter_var function, the default value was incorrectly passed.
By default, null is passed, but an array or integer is expected.
Soft type casting may mask future problems.

Changes:

• Updated variable types in docBlock
• Added nullable type for filter parameter
• Defined a default value for the filter and flag arguments if passed null.
• The filter and flag arguments are cast to the expected types.
• Adjusted the data validation condition based on the changes above.

Checklist:

• Securely signed commits
• Component(s) with PHPdocs
• Unit testing, with >80% coverage
• User guide updated
• Conforms to style guide

[paulbalandan]

Please rebase.

[iRedds]

@paulbalandan Looks like I did something wrong.

[paulbalandan]

I'm not sure how to fix this but I guess you need to cherry pick your PR commit adfa1ec

[totoprayogo1916]

just run this @iRedds

git fetch upstream
git rebase upstream/develop

after that, become like this:

then run git push -f

FYI: I have test with your branch

[iRedds]

I think I did it.
Thx @totoprayogo1916