Adds network UI test framework

This adds a test framework to drive UI tests from the client
instead of injecting events from the websocket.  Tests consist
of a pair of snapshots (before and after the test) and
a list of UI events to process.  Tests are run using a FSM
in the client that controls the resetting of state to the snapshot,
injecting the events into the UI, recording test coverage,
and reporting tests to the server.

* Adds design for event trace table
* Adds design for a coverage tracking table
* Adds models for EventTrace and Coverage
* Adds trace_id to recording messages
* Adds design for TopologySnapshot table
* Adds order to TopologySnapshot table
* Adds TopologySnapshot table
* Adds Snapshot message when recordings are started and stoppped
* Adds models for tracking test cases and test results
* Adds designs for a test runner FSM
* Updates test management commands with new schema
* Adds download recording button
* Adds models to track tests
* Adds ui test runner
* Adds id and client to TestResult design
* Adds id and client to TestResult
* Update message types
* Stores test results and code coverage from the test runner
* Adds tool to generate a test coverage report
* Adds APIs for tests and code coverage
* Adds per-test-case coverage reports
* Breaks out coverage for loading the modules from the tests
* Re-raises server-side errors
* Captures errors during tests
* Adds defaults for host name and host type
* Disables test FSM trace storage
* Adds support for sending server error message to the client
* Resets the UI flags, history, and toolbox contents between tests
* Adds istanbul instrumentation to network-ui

awx/ui/client/src/network-ui/style.less

@@ -766,3 +766,8 @@
 .NetworkUI__contextMenuButton-pressed{
     fill:@button-body-hover;
 }
+
+.NetworkUI__test_results {
+    fill: @light-background;
+    stroke: @dark-widget-detail;
+}