ChunkStore: implement new component-less indices and APIs

[teh-cmc]

Introduces new component-less indices and APIs that allow for efficiently searching for relevant chunks directly at the entity level, as opposed to the entity+component level.

cc @jprochazk

/// Returns the most-relevant _temporal_ chunk(s) for the given [`LatestAtQuery`].
///
/// The returned vector is guaranteed free of duplicates, by definition.
///
/// The [`ChunkStore`] always work at the [`Chunk`] level (as opposed to the row level): it is
/// oblivious to the data therein.
/// For that reason, and because [`Chunk`]s are allowed to temporally overlap, it is possible
/// that a query has more than one relevant chunk.
///
/// The caller should filter the returned chunks further (see [`Chunk::latest_at`]) in order to
/// determine what exact row contains the final result.
///
/// **This ignores static data.**
pub fn latest_at_relevant_chunks_for_all_components(
    &self,
    query: &LatestAtQuery,
    entity_path: &EntityPath,
) -> Vec<Arc<Chunk>> {
    // ...
}

/// Returns the most-relevant _temporal_ chunk(s) for the given [`RangeQuery`].
///
/// The returned vector is guaranteed free of duplicates, by definition.
///
/// The criteria for returning a chunk is only that it may contain data that overlaps with
/// the queried range.
///
/// The caller should filter the returned chunks further (see [`Chunk::range`]) in order to
/// determine how exactly each row of data fit with the rest.
///
/// **This ignores static data.**
pub fn range_relevant_chunks_for_all_components(
    &self,
    query: &RangeQuery,
    entity_path: &EntityPath,
) -> Vec<Arc<Chunk>> {
    // ...
}

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[jprochazk]

Tested by temporarily merging into my PR, works well