Fix incorrect assertion in input_test::test_set()

$INPUT is set to 'test2', but the $_POST checks for 'test'.

Fix various errors in PHPUnit tests on PHP 8

adjusted the Input clases for PSR2

They are now in their own namespace.

added filter method to INPUT class

the filter() function can be chained between the accessor and the value
function to get a filtered value. When no filter allable is given in the
filter() function,

added filter method to INPUT class

the filter() function can be chained between the accessor and the value
function to get a filtered value. When no filter allable is given in the
filter() function, stripctl() is used to strip all control chars (ASCII<32)

Examples:

$INPUT->post->filter()->str('foobar');
$INPUT->get->filter('myfilter')->int('baz');

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added another test for arrays

add new valid() method to $INPUT #667

extract method for Input class

makes it easier to access our do parameters

treat empty string inputs as unset for int and bool

some Input class fixes and unit tests