Removed usage of PyYAML for config parsing. (#13883)

* Ignore entire __pycache__ folder instead of individual *.pyc files

* Ignore .mypy_cache in git

* Rework config YAML parsing to use only ruamel.yaml

PyYAML silently overrides keys when encountering duplicates, but ruamel
raises and exception by default. Since we're already using it elsewhere,
dropping PyYAML is an easy choice to make.

* Added EnvString in config to slim down runtime_config()

* Added gitlens to devcontainer

* Automatically call FrigateConfig.runtime_config()

runtime_config needed to be called manually before. Now, it's been
removed, but the same code is run by a pydantic validator.

* Fix handling of missing -segment_time

* Removed type annotation on FrigateConfig's parse

I'd like to keep them, but then mypy complains about some fundamental
errors with how the pydantic model is structured. I'd like to fix it,
but I'd rather work towards moving some of this config to the database.

frigate/api/app.py

@@ -248,7 +248,7 @@ def config_save():
 
     # Validate the config schema
     try:
-        FrigateConfig.parse_raw(new_config)
+        FrigateConfig.parse_yaml(new_config)
     except Exception:
         return make_response(
             jsonify(
@@ -336,7 +336,7 @@ def config_set():
             f.close()
         # Validate the config schema
         try:
-            config_obj = FrigateConfig.parse_raw(new_raw_config)
+            config_obj = FrigateConfig.parse_yaml(new_raw_config)
         except Exception:
             with open(config_file, "w") as f:
                 f.write(old_raw_config)
@@ -361,8 +361,8 @@ def config_set():
     json = request.get_json(silent=True) or {}
 
     if json.get("requires_restart", 1) == 0:
-        current_app.frigate_config = FrigateConfig.runtime_config(
-            config_obj, current_app.plus_api
+        current_app.frigate_config = FrigateConfig.parse_object(
+            config_obj, plus_api=current_app.plus_api
         )
 
     return make_response(