Simple search interface

[jpmckinney]

• Change page title to something like "Search for entities across 5 influence data APIs"

Request:

• Collect filters, operators
• Checkboxes to select publishers to query
• Collect limit
• Collect any necessary API keys (store in cookie?)
• Implement pagination (see Deal with pagination whos_got_dirt-gem#6)

Response:

• Display results
• Display results in tabular format
• Add spinner
• Add source column with link to individual record (add feature to gem)
• Clicking "Details" shows JSON
• Display messages in response
• Display HTTP error
• Display the queries submitted to the APIs (from sources in response)
• Download results as CSV (add feature to server)