Allow users to create their own filters

[jlaw9]

Often users would like to be able to filter or show results based on different threshold values or settings in their data (such as an edge weight filter). Currently GraphSpace supports a k or rank filter. Ideally, each user would be able to set their own filters based on their data.

Here's my idea:
Add a 'filters' array in the JSON object to upload which stores a map for each filter. Each filter key is the name of the filter to show on GraphSpace, and the value is the name of the attribute (required to be present on all nodes and edges) for which to create the filter.

Then GraphSpace will automatically create a sliding bar for each of the specified filters.

[adbharadwaj]

Once we upgrade cytoscape.js #378 we can add filter box like search box which will allows users to filter by entering queries.