selectCategoricalOption mutation for Phase 2 Store Refactor

[jarmoza]

This PR closes #274 by implementing the following:

1. selectCategoricalOption mutation in the store that takes a column name, option value and raw value and a) creates a valueMap object on dataDictionary.annotated.<column_name> if it does not exist, and b) assigns the raw value and option value as a key/value pair in the valueMap object.
2. Three unit tests in store-mutation-selectCategoricalOption.cy.js that test a) if the value map is created when it does not yet exist, b) if the option (annotated) value is set in the value map for the raw value, and c) ensures a previously entered option value can be overwritten in the value map.
3. annot-categorical component and its component test in annot-categorical.cy.js are updated to reflect changes for the new selectCategoricalOption mutation

[rmanaem]

👨🏼‍🍳 🥯