Aggregate selected data on Build Query Button click

[Maartenvm]

• Changed allreducers from combinedReducer to slicedReducer form to allow sharing of state,
• Added Button to manually gather selected nodes.

State space is now:
state:
    entities: {
        textSearchResults: string[],
        [number] objectId ...
    },
    events: {
        textSearchResults: string[],
        [number] objectId ...
    },
    topics: {
        textSearchResults: string[],
        [number] objectId ...
    },
    sources: {
        textSearchResults: string[],
        [number] objectId ...
     },
    queryState: {
        isQueryBuildDialogOpen : boolean,
        isQueryClearDialogOpen: boolean,
        isQueryDialogOpen: boolean,
        queryString: string,
        selectedMentionCount: number,
        entities: [],
        events: [],
        topics: [],
        sources: []
    }
}

• Further logic behind query build action needed.

[jspaaks]

• FYI the behavior in FF is weird
• what server.js do you use for this? mine has trouble with this line.
• also in server.js, are you using storyteller2.db or storyteller.db?
• if I do npm start in query-builder-server and an npm start in query-builder-client, then point chrome to localhost:3000, I get the page but if I click owl/thing for example, it doesn't expand. When I then focus the search widget and doe a search for Agent, then click owl/thing, it does expand.
• checkbox filterstate doesn't show correctly anymore. looks more like a problem with the rendering that the browser does. I sometimes get half a minus sign for example, or just one pixel instead of a minus. the full checkmark does work. Problem occurs when rendering a partial select at 90% zoomlevel
• biggest problem with the code is there are too many connected components, but that is both in master and in this branch so perhaps not relevant to the current PR