Relocate Resource to org.junit.platform.commons.io package

[marcphilipp]

This PR introduces a new Resource interface in the new org.junit.platform.commons.io package.

The old interface extends the new one so it can be used in places that now consume the new interface.

The resource finding/scanning methods in ReflectionSupport are now deprecated in favor of the new ones in the ResourceSupport class.

Since Predicate<...io.Resource> and Predicate<...support.Resource> have the same erasure, this PR introduces ResourceFilter (mimicking the existing ClassFilter) in order to be able to overload methods such as EngineDiscoveryRequestResolver.Builder.addResourceContainerSelectorResolver.

Resolves #4885.

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Definition of Done

• There are no TODOs left in the code
• Method preconditions are checked and documented in the method's Javadoc
• Coding conventions (e.g. for logging) have been followed
• Change is covered by automated tests including corner cases, errors, and exception handling
• Public API has Javadoc and @API annotations
• Change is documented in the User Guide and Release Notes

[sormuras]

Looks okay - and it's always good to see "ignore" directives vanish from ArchUnit tests.

[sbrannen]

Suggested change

	public boolean equals(Object obj) {
	if (obj == this) {
	return true;
	}
	if (obj instanceof org.junit.platform.commons.io.Resource that) {
	return name.equals(that.getName()) //
	&& uri.equals(that.getUri());
	}
	return false;
	}
	public boolean equals(Object obj) {
	return obj == this || (obj instanceof org.junit.platform.commons.io.Resource that
	&& this.name.equals(that.getName()) && this.uri.equals(that.getUri()));
	}

I tend to prefer the above "this and that" pattern when using instanceof pattern matching.