Increase file upload limit to 100 MB (#77117)

* Increase file upload limit to 100 MB

* Remove comment

* Add test and fix chunk processing

* Add test for wrong field

* Add review suggestions

* Use nonlocal and remove unneeded executor task

* Use Janus to process chunk uploading

* Address review comments

* Address review comments #2

* Improve tests

* Fix discovery test

* Fix tests

tests/components/file_upload/conftest.py

@@ -0,0 +1,13 @@
+"""Fixtures for FileUpload integration."""
+from io import StringIO
+
+import pytest
+
+
+@pytest.fixture
+def large_file_io() -> StringIO:
+    """Generate a file on the fly. Simulates a large file."""
+    return StringIO(
+        2
+        * "Home Assistant is awesome. Open source home automation that puts local control and privacy first."
+    )