Bundle aggregations outside of the serialization method. (#11612)

This makes the serialization of events synchronous (and it no
longer access the database), but we must manually calculate and
provide the bundled aggregations.

Overall this should cause no change in behavior, but is prep work
for other improvements.

1 files changed, 1 insertions, 0 deletions

diff --git a/changelog.d/11612.misc b/changelog.d/11612.misc
new file mode 100644
index 0000000000..2d886169c5
--- /dev/null
+++ b/changelog.d/11612.misc
@@ -0,0 +1 @@
+Avoid database access in the JSON serialization process.