move sql-only functions to plpgsql instead of using SPI #1203

Job	Run time
test_extras (ubuntu-22.04, 15)	15m 29s
test_lantern (ubuntu-22.04, 12)	21m 43s
test_extras (ubuntu-22.04, 17)	15m 1s
test_extras (ubicloud-standard-4-arm, 15)	1m 52s
test_lantern (ubuntu-22.04, 13)	23m 39s
test_extras (ubicloud-standard-4-arm, 17)	2m 6s
test_lantern (ubuntu-22.04, 14)	27m 27s
test_lantern (ubuntu-22.04, 15)	23m 10s
test_lantern (ubuntu-22.04, 16)	24m 37s
test_lantern (ubuntu-22.04, 17)	15m 51s
test_lantern (ubicloud-standard-4-arm, 12)	26m 50s
test_lantern (ubicloud-standard-4-arm, 13)	28m 49s
test_lantern (ubicloud-standard-4-arm, 14)	30m 42s
test_lantern (ubicloud-standard-4-arm, 15)	28m 23s
test_lantern (ubicloud-standard-4-arm, 16)	28m 22s
test_lantern (ubicloud-standard-4-arm, 17)	17m 13s
test_lantern (macos-13, 12)	5m 48s
test_lantern (macos-13, 13)	5m 15s
test_lantern (macos-13, 14)	6m 50s
test_lantern (macos-13, 15)	7m 34s
test_lantern (macos-13, 16)	5m 43s
test_lantern (macos-13, 17)	7m 55s
upload_coverage	0s
	6h 10m 19s

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