The rationale is the same as in
6d325651dc. Due to the recursive nature of
`GameplaySampleTriggerSource.GetMostValidObject()`, in the case of
nested hits, drum rolls and drum roll ticks, the nested strong hits
would become the most valid object, and so without propagating
the samples down to that level too, nothing would play.
In d97daee96b, `DrumSampleTriggerSource`
was changed such that in order to play sounds for the user's inputs, the
bank of the normal sound would always be used.
The problem is that in the case of taiko objects which have nested
objects (swells and drum rolls), the samples were not propagated fully
(drum rolls, where only the finish sample was kept, for the purposes of
determining strongability), or not propagated at all (swells) to ticks.
As ticks of both objects are valid return values of
`GetMostValidHitObject()`, this would lead to the drum making no sounds
if the next object was a drum roll or swell, until that drum roll or
swell was completed. To fix, propagate the full set of samples, so that
`DrumSampleTriggerSource` can retrieve the normal sound to copy the bank
from.
Note that this may not necessarily reproduce prior behaviour. This is
because it is not guaranteed that all realised samples for a given
hitobject have the same bank - some may have been overriden locally on a
given hitobject. Previously, the bank would have been retrieved from the
sample control point, wherein there is only one possible bank to use;
however, when deciding the sound to play on the basis of a constructed
hitobject, it is possible that there are cases wherein the hitnormal
sample was overridden on that given hitobject, and in such cases, this
PR would make samples _play_, but not necessarily the _same_ samples
as prior to #23308.
If that turns out to be the case, this will have to be revisited.
