gh-209: Replace MockAccumuloStore usages in docs with MapStore

[t92549]

null

Related Issue

• Resolve Replace MockAccumuloStore usage #209

[t92549]

Blocked until gchq/Gaffer#2520 is merged and pulled into gaffer-docs

[t92549]

It is worth noting that as this replaces the MockAccumuloStore with the MapStore, a few features that were documented are not supported by the MapStore and therefore, the code was not run but just printed into the docs. These examples are all under the accumulo and spark operation examples, e.g.:

gaffer-doc/src/main/java/uk/gov/gchq/gaffer/doc/operation/accumulo/GetElementsBetweenSetsExample.java

Lines 41 to 56 in 3f3b943

	public void getElementsWithinSetOfVertices1And2And4() {
	// ---------------------------------------------------------
	final GetElementsBetweenSets operation = new GetElementsBetweenSets.Builder()
	.input(new EntitySeed(1))
	.inputB(new EntitySeed(2), new EntitySeed(4))
	.build();
	// ---------------------------------------------------------
	showExample(operation, null);
	print("The results are:\n");
	print("```");
	print("Entity[vertex=1,group=entity,properties=Properties[count=<java.lang.Integer>3]]\n" +
	"Edge[source=1,destination=2,directed=true,matchedVertex=SOURCE,group=edge,properties=Properties[count=<java.lang.Integer>3]]\n" +
	"Edge[source=1,destination=4,directed=true,matchedVertex=SOURCE,group=edge,properties=Properties[count=<java.lang.Integer>1]]");
	print("```");
	}

Here, the code is not run but the results that were generated are just printed. This is okay as the docs are soon to be all replaced with text anyway.

[t92549]

The MapStore was chosen as the replacement instead of MiniAccumuloStores for a few reasons.
Firstly, MapStores are more lightweight to start up and the standard store for testing.
Secondly, the MiniAccumuloStore right now is a test dependency within Gaffer and it is awkward to directly import it and setup a MiniAccumuloCluster during the building of the docs, like how it works when the Gaffer tests run.

To accommodate these changes, a few parts of the docs had to be "faked" where the operations do not exist within the MapStore (see above #237 (comment)).
As well as this, it was discovered that a few parts of the MapStore had bugs in or did not behave the same as AccumuloStore, so these were fixed and released first: gchq/Gaffer#2421 and gchq/Gaffer#2519