Adds Geospatial custom fields and Map/Attribute viewer to Record view

[spilth]

This is the beginning of adding Geospatial functionality to UltraViolet.

This PR includes the following functionality/features:

• Adds custom fields for GeoServer layer name, WMS/WFS layer availability and bounding box
• Adds a Leaflet Map, attributes list and web services detail views for geospatial records
• Adds the ability for users to click feature to see their attributes
• Adds a GeoServer proxy for WFS requests (attributes list and feature details)
• Prevents anonymous users from seeing map, attributes and web service details for restricted records
• Adds view tests for the above

Addresses #209, #210, #211 and #212

Note: I'd prefer to squash this before merging it, so I'd like to merge it myself once it's approved.

Screenshots

Custom Fields Editing

Restricted Record

Public Record

[spilth]

These are here to allow pulling content from external sources on the front-end.

[spilth]

This is only enabled in local and to allow bulk loading data via the REST API.

[ekate]

We might ask somebody else to look at javascript/css part, everything else looks good to me.

[dismorfo]

Hi there. The code looks good. Since we don't have a linter rules file or a document outlining best practices, I will keep it short.

Error Handling: The fetch call log errors to the console instead of using user-friendly messages or retry mechanisms. Try contacting @lhenze and asking her about UI expectations when fetch fails.

Comments: Add comments to the code. This is a suggestion since we don't have a document describing how to document our work.