Add operator aspect to crafting writer

[harshverma27]

Closes #76.

Changes

This PR adds a new aspect to the crafting writer: "Craft Recipe from Operator".

• The aspect takes an operator without inputs. The operator must give a recipe.
• On each update, the writer runs the operator and crafts the recipe that it gives.
• If the recipe is empty, the writer does not craft.
• If the operator needs inputs or does not give a recipe, the writer shows an error.

The aspect uses the same settings and craft logic as "Craft Recipe" (PROP_CRAFT_RECIPE).
The model uses the texture of "Craft Recipe". I did not add a new texture.

Tests

I added three game tests to GameTestsItemsCraft:

• testItemsCraftChestOneOperator: the operator gives the chest recipe. The writer crafts one chest.
• testItemsCraftChestOneOperatorEmptyRecipe: the operator gives an empty recipe. The writer does not craft and shows no error.
• testItemsCraftOperatorWithInputs: the operator needs an input. The writer shows an error.

To make an operator without inputs, the tests apply a recipe to the id operator.

Validation

• ./gradlew build passes.
• ./gradlew runGameTestServer passes all 79 required tests.

[CLAassistant]

All committers have signed the CLA.

[harshverma27]

@rubensworks Hi, just did the changes as we talked about in #76.

[rubensworks]

Thanks @harshverma27, looks perfect! Will publish new releases soon.

[harshverma27]

@rubensworks Thanks, I'll see #20 now.