GUI app (experimental) (#730)

* add default config

* first pass

* flake8

* cleanup

* first pass at using qthreads

* cleanup

* WIP

* better error handling

* improved UI

* bugfix

* fix merge bugs

* import order

* cleanup

* make gui requirements optional

* pr review requested changes

* Update server/gui/main.py

Co-Authored-By: csweaver <charlottesweaver@gmail.com>

* pr review request

* qt child class methods -> camelCase

* whitespace

server/gui/utils.py

@@ -0,0 +1,21 @@
+import platform
+
+from PyQt5.QtCore import QObject, pyqtSignal
+
+# Detect OS
+WINDOWS = (platform.system() == "Windows")
+LINUX = (platform.system() == "Linux")
+MAC = (platform.system() == "Darwin")
+
+
+class WorkerSignals(QObject):
+    """
+    Defines the signals available from a running worker thread.
+    Supported signals are:
+        finished
+        error - `str` error message
+        result - `object` data returned from processing, anything
+    """
+    finished = pyqtSignal()
+    error = pyqtSignal(str)
+    result = pyqtSignal(object)