Add vararg helper methods for multi-tag support in the FabricTagBuilder

[Starexify]

This makes it possible to use multiple arguments in the new addTags methods so that modders using datagen _{(like me)} no loger have to call the addTag() method for each TagKey<T>.

This PR will add the following vararg methods:

/**
 * Add multiple tags to this tag.
 *
 * @return the {@link FabricTagBuilder} instance
 */
@SafeVarargs
public final FabricTagBuilder addTags(TagKey<T>... tags) {
	for (TagKey<T> tag : tags) {
		addTag(tag);
	}

	return this;
}

/**
 * Add multiple optional tags to this tag.
 *
 * @return the {@link FabricTagBuilder} instance
 */
@SafeVarargs
public final FabricTagBuilder addOptionalTags(TagKey<T>... tags) {
	for (TagKey<T> tag : tags) {
		addOptionalTag(tag);
	}

	return this;
}

/**
 * Add multiple tags to this tag, ignoring any warning.
 *
 * <p><b>Note:</b> only use this method if you are sure that the tags will be always available at runtime.
 * If not, use {@link #addOptionalTags(TagKey[])} instead.
 *
 * @return the {@link FabricTagBuilder} instance
 */
@SafeVarargs
public final FabricTagBuilder forceAddTags(TagKey<T>... tags) {
	for (TagKey<T> tag : tags) {
		forceAddTag(tag);
	}

	return this;
}

Also changed the JavaDocs at line 421 to link the addOptionalTag(TagKey<T>) instead of * If not, use {@link #addOptionalTag(Identifier)} instead.

Also changed the add(T... elements) method to use a for loop instead of a Stream.of():

@SafeVarargs
public final FabricTagBuilder add(T... elements) {
	for (T element : elements) {
		add(reverseLookup(element));
	}

	return this;
}

[modmuss50]

Just some checkstyle failuires now, you need a blank line after the for loop.