dynamo-browse: Background queries

[lmika]

Have the ability to run background queries. These are queries that are launched in the background that may take a while to run.

The way this will work is as follows. When the user indicates they want to start a background query:

1. They will be presented with a form where they can enter the following details:
   • The query they want to run
   • Any throttling they'd like to use. I.e. run as fast as possible, get a page every 3 seconds, etc.
2. They will be presented with an option to test the query. This will run the query with a limit of 5 rows and a max duration of 30 seconds.
3. They will then execute the query.

The query will run in the background with a status indicator in the status bar. As the query runs, the results will be written to the workspace.

Once the query is done, the user will be given the option to view the query results.