Operate natively on SparseArraySeed objects

WARNING: SparseArraySeed objects are defunct in BioC >= 3.21!

Some utilities to operate natively on SparseArraySeed objects. Mostly for internal use by the DelayedArray package e.g. they support block processed methods for sparse DelayedArray objects like sum(), mean(), which(), etc...

Examples

## WARNING: SparseArraySeed objects are defunct in BioC >= 3.21!