Macro commit

* Fixed Options for extra_params in UI
* Enhanced meta-programming for models
* Plugins can be imported from a python file if they're named
`senpy_<whatever>.py>` (no need for `.senpy` anymore!)
* Add docstings and tests to most plugins
* Read plugin description from the docstring
* Refactor code to get rid of unnecessary `.senpy`s
* Load models, plugins and utils into the main namespace (see __init__.py)
* Enhanced plugin development/experience with utils (easy_test, easy_serve)
* Fix bug in check_template that wouldn't check objects
* Make model defaults a private variable
* Add option to list loaded plugins in CLI
* Update docs

example-plugins/sleep_plugin.py

@@ -0,0 +1,27 @@
+from senpy.plugins import AnalysisPlugin
+from time import sleep
+
+
+class Sleep(AnalysisPlugin):
+    '''Dummy plugin to test async'''
+    author = "@balkian"
+    version = "0.2"
+    timeout = 0.05
+    extra_params = {
+        "timeout": {
+            "@id": "timeout_sleep",
+            "aliases": ["timeout", "to"],
+            "required": False,
+            "default": 0
+        }
+    }
+
+    def activate(self, *args, **kwargs):
+        sleep(self.timeout)
+
+    def analyse_entry(self, entry, params):
+        sleep(float(params.get("timeout", self.timeout)))
+        yield entry
+
+    def test(self):
+        pass