Make EventBus Timeout Configurable

[kkoz]

The default timeout for a VertX EventBus request is 30 seconds. Previously, there was no way to change this value in the microservice.

With this PR, it is now possible to add/edit the new event_bus_timeout configuration property to set the EventBus timeout (in ms).

Testing

To test, you'll need to perform a request that takes between 30s and 60s (which is the default NGINX timeout).
You can start by creating this test file:

test&sizeX=2304&sizeY=2304&sizeZ=12&sizeC=3&pixelType=uint16&sleepOpenBytes=1000.fake

And then importing it.

Then run webgateway/render_image_region requests against it with a projection, e.g.

http://localhost:8085/webgateway/render_image_region/1051/0/0/?m=c&t=1&c=1|0:255$FF0000,2|0:255$00FF00,3|0:255$0000FF&z=1&tile=0,0,0,64,64&p=intmax|0:10

Without this PR, anything over 30s will fail. With it and with the config set, it should succeed.