default push notifications to be noisy

[Reaster0]

some servers (continuwuity) don't send any actions/tweaks in the push notifications after push registration using the flag event_id_only that discard them (just as synapse btw),

in that case they send push notifications without filling the "tweaks" field https://spec.matrix.org/v1.17/push-gateway-api/#post_matrixpushv1notify_request_device

other clients like fluffychat, element classic, etc default this situation to noisy notifications but element x default to silent (because of the behaviour of this lib) in that case there's no way to get noisy notifications on element x and continuwuity,

more informations about this issue can be found there:
element-hq/element-x-ios#5132
https://forgejo.ellis.link/continuwuation/continuwuity/issues/1533
https://forgejo.ellis.link/continuwuation/continuwuity/issues/1424

[codspeed-hq]

Merging this PR will not alter performance

✅ 50 untouched benchmarks

---

_{Comparing Reaster0:default-noisy-push (cd37aa1) with main (791f4bc)}

[BillCarsonFr]

@Reaster0
Can you provide the default push rules set created by continuwuity? just to check if there is a difference with synapse

[BillCarsonFr]

There are some ongoing investigation regarding that here element-hq/element-x-ios#5132 (comment)
Apparently continuwuity and synapse use slightly different default pushrules. This can explain alone the difference of behavior. This needs more investigations and maybe spec clarifications

[Reaster0]

better/cleaner pr that include the tests here: #6281