Add sparse matrix interface #1999

Job	Run time
Ruff	7s
Typos	7s
Pytest Conda Py3 POCL	3m 1s
Pytest Conda Py3 Intel	2m 39s
basedpyright	2m 7s
Examples Conda Py3	1m 43s
Documentation	2m 7s
Tests for downstream project mirgecom_examples	4s
Tests for downstream project grudge	12m 0s
Tests for downstream project meshmode	10m 32s
Tests for downstream project mirgecom	6s
	34m 33s

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