Optimize Store.initRecord to avoid redundant get() calls

The add() and insert() methods in Neo.data.Store now default to returning record instances (init=true). This means initRecord() is called more frequently with items that might already be record instances.

Currently, initRecord() calls this.get(), which internally checks if the item is a record. To avoid this unnecessary method call and lookup, we should add an explicit check in initRecord():

initRecord(data) {
    if (RecordFactory.isRecord(data)) {
        return data;
    }
    return this.get(data[this.getKeyProperty()])
}

This optimizes the common path where records are already present.