List plugins and streams by their names in server config

Currently, accessing a plugin's or stream's config from outside their creation requires iterating through the list of plugins/streams in order to find the one that matches what you're looking for, because their configs are in a yaml list where every element is generically named plugin or stream. It would allow for easier access if they were listed by their name.

For example, instead of

    server:
         plugins:
             - plugin:
                 name: ait.gui.AITGUIPlugin
                 inputs:
                     - telem_stream
                     - log_stream
                 outputs:
                     - command_stream

it would be

    server:
         plugins:
             - ait.gui.AITGUIPlugin:
                 inputs:
                     - telem_stream
                     - log_stream
                 outputs:
                     - command_stream

Start by locating the server configuration parser and the YAML handling for plugins and streams. Compare the current generic plugin/stream list shape with the name-keyed shape shown in the issue; done means the requested configuration form is accepted and external lookup no longer requires iterating through the lists.