show all tasks in dependency graph [feature request]

[joooeey]

It would be sweet to be able to view all tasks connected to a task (downstream and upstream) at once in the dependency graph. Right now you have to use the "Show Upstream Dependencies" toggle to toggle between them but you can't view the whole graph.

To take this a step further, it would be even sweeter if you can view all tasks in the dependency graph even if they're not connected at all. In the beginning I found it really confusing that when you click on the "Dependency Graph" tab, you only see an empty window (see below). Perhaps one can add a "Load all" button there, so you don't accidentally trigger a big workload for the browser and server as discussed in #1622.