The `wildcard()` function tests whether the given wildcard pattern matches
the given subject, optionally ignoring letter case.

Returns `true` if the pattern matches the subject.

Returns `false` if the pattern does not match the subject.

Returns `null` if the pattern argument is not a string value.

-- Testcase --
{%
	printf("%.J\n", [
		// A simple glob pattern match
		wildcard("file.txt", "*.txt"),

		// Using `?` as single character placeholder and case folding
		wildcard("2022-02-02_BACKUP.LIST", "????-??-??_backup.*", true),

		// Using bracket expressions
		wildcard("aaa_123_zzz", "[a-z][a-z][a-z]_???_*"),

		// Using no meta characters at all
		wildcard("test", "test"),

		// No match yields `false`
		wildcard("abc", "d*"),

		// Invalid pattern value yields `null`
		wildcard("true", true)
	]);
%}
-- End --

-- Expect stdout --
[
	true,
	true,
	true,
	true,
	false,
	null
]
-- End --