Ability to configure min frames for zone presence (#6680)

* Objects need to be in zones multiple times to be considered present in the zone

* Add a field to configure inertia per zone

* Formatting

* Use correct default method

* Clarify zone presence behavior

Co-authored-by: Blake Blackshear <blakeb@blakeshome.com>

---------

Co-authored-by: Blake Blackshear <blakeb@blakeshome.com>

frigate/config.py

@@ -330,6 +330,12 @@ class ZoneConfig(BaseModel):
     coordinates: Union[str, List[str]] = Field(
         title="Coordinates polygon for the defined zone."
     )
+    inertia: int = Field(
+        default=3,
+        title="Number of consecutive frames required for object to be considered present in the zone.",
+        gt=0,
+        le=10,
+    )
     objects: List[str] = Field(
         default_factory=list,
         title="List of objects that can trigger the zone.",