[StaticTypeMapper] Map phpstan-special scalar types (literal-string, numeric-string, ...)

[TomasVotruba]

Several PHPStan-special types were missing from ScalarStringToTypeMapper, so they fell through to a bogus ObjectType('...'). RemoveReturnTagIncompatibleWithNativeTypeRector then saw the native type as not a supertype of that bogus object and wrongly deleted the more precise docblock.

Mapping each to its real PHPStan type (same pattern as the existing non-empty-string / class-string mappings) makes them genuine subtypes, so the rule now keeps them.

Newly mapped types

PHPDoc type	Mapped to
literal-string	AccessoryLiteralStringType
numeric-string	AccessoryNumericStringType
non-falsy-string, truthy-string	AccessoryNonFalsyStringType
lowercase-string	AccessoryLowercaseStringType
uppercase-string	AccessoryUppercaseStringType
non-negative-int	int<0, max>
non-positive-int	int<min, 0>
array-key	int|string

Before (rule wrongly removed the precise type)

-    /**
-     * @return literal-string
-     */
     public function getTableAlias(): string
     {
         return 'n';
     }

After

    /**
     * @return literal-string
     */
    public function getTableAlias(): string
    {
        return 'n';
    }

Docblock kept — literal-string (and the others above) are legitimate narrowings of their native type.