Increase maximum event sub_label length to 100 characters (#6350)

* Increase maximum sub label length to 100 characters and update corresponding fields in models and API

* black format...

migrations/016_sublabel_increase.py

@@ -0,0 +1,12 @@
+import peewee as pw
+from playhouse.migrate import *
+from playhouse.sqlite_ext import *
+from frigate.models import Event
+
+
+def migrate(migrator, database, fake=False, **kwargs):
+    migrator.change_columns(Event, sub_label=pw.CharField(max_length=100, null=True))
+
+
+def rollback(migrator, database, fake=False, **kwargs):
+    migrator.change_columns(Event, sub_label=pw.CharField(max_length=20, null=True))