New Federated StoreConfigured files cannot be set

[t92549]

Describe the bug
The new FederatedStore StoreConfigured options cannot be set to files outside the resources. These are storeConfiguredMergeFunctions and storeConfiguredGraphIds.

To Reproduce
Steps to reproduce the behavior:

1. Set gaffer.federatedstore.storeConfiguredMergeFunctions property to a full path
2. It will not be loaded as it was not part of resources when built

Expected behavior
It should accept full paths like operationDeclarations

Additional context

Gaffer/store-implementation/federated-store/src/main/java/uk/gov/gchq/gaffer/federatedstore/util/FederatedStoreUtil.java

Lines 375 to 389 in a5f3804

	public static List<String> loadStoreConfiguredGraphIdsListFrom(final String path) throws IOException {
	if (isNull(path)) {
	return null;
	} else {
	return JSONSerialiser.deserialise(IOUtils.toByteArray(StreamUtil.openStream(FederatedStoreUtil.class, path)), List.class);
	}
	}
	public static Map<String, BiFunction> loadStoreConfiguredMergeFunctionMapFrom(final String path) throws IOException {
	if (isNull(path)) {
	return Collections.emptyMap();
	} else {
	return JSONSerialiser.deserialise(IOUtils.toByteArray(StreamUtil.openStream(FederatedStoreUtil.class, path)), SerialisableConfiguredMergeFunctionsMap.class).getMap();
	}
	}

[t92549]

Closed by #2878