Deprecate and remove SPACE case for NotEmpty validator

[Xerkus]

NotEmpty validator considers string ' ' empty by default due to space case. It is a surprising behavior that apparently got inherited from ZF1 over 12 years ago.

laminas-validator/src/NotEmpty.php

Lines 64 to 71 in fac99d7

	protected $defaultType = [
	self::OBJECT,
	self::SPACE,
	self::NULL,
	self::EMPTY_ARRAY,
	self::STRING,
	self::BOOLEAN,
	];

In case of laminas-inputfilter it would be a filter responsibility to remove spaces or anything else like line feed before validation.

I would say this condition is useful only for laminas-form and only for a sloppy input filter definitions. This case should really be handled by the trim filter.

[gsteel]

I kind of agree, but validator does not depend on filter or input-filter - I don't think it's unreasonable to consider as a validation failure by default. You could make the argument that input should be filtered by the ToNull filter which would negate the need for self::STRING and self::EMPTY_ARRAY too probably.

If you have strong feelings here, v3 is getting pretty close…