The previous implementation of `SampleInfo`'s equality members was not
completely correct in its treatment of the `sampleNames` array. While
`Equals()` compared the values of `sampleNames` using `SequenceEqual()`,
therefore performing a structural check that inspects the contents of
both arrays, `GetHashCode()` used `HashCode.Combine()` directly on the
arrays, therefore operating on reference equality. This could cause the
pooling mechanism of samples to fail, as pointed out in #11079.
To resolve, change the `GetHashCode()` implementation such that it also
considers the contents of the array rather than just the reference to
the array itself. This is achieved by leveraging
`StructuralEqualityComparer`.
Additionally, as a bonus, an array sort was added to the constructor of
`SampleInfo`. This is intended to be a "canonicalisation" processing
step for the array of sample names. Thanks to that sort, two instances
of `SampleInfo` that have the same sample names but permutated will also
turn out to be equal and have the same hash codes, given the
implementation of both equality members. This gives `SampleInfo`
set-like semantics.
This is a temporary solution for now that uses DrawableHitObject.SampleNamespace for the override. We will not want to do this going forward, and instead have the rulesets add their custom resource stores to the games', but that requires deciding where/when to apply/remove such resource stores, and is probably left to skinning.
