Consolidate shared code into PdoAdapter #822

Job	Run time
Windows - PHP 8.1 & SQL Server	1m 58s
testsuite-linux (8.1, mariadb)	1m 26s
testsuite-linux (8.1, mysql)	48s
testsuite-linux (8.1, pgsql)	55s
testsuite-linux (8.1, sqlite)	38s
testsuite-linux (8.2, mariadb)	2m 5s
testsuite-linux (8.2, mysql)	49s
testsuite-linux (8.2, pgsql)	45s
testsuite-linux (8.2, sqlite)	40s
testsuite-linux (8.3, mariadb)	1m 37s
testsuite-linux (8.3, mysql)	1m 44s
testsuite-linux (8.3, pgsql)	48s
testsuite-linux (8.3, sqlite)	1m 6s
testsuite-linux (8.4, mariadb)	1m 29s
testsuite-linux (8.4, mysql)	1m 4s
testsuite-linux (8.4, pgsql)	44s
testsuite-linux (8.4, sqlite)	41s
testsuite-linux (8.1, sqlite, prefer-lowest)	38s
testsuite-linux (8.1, sqlite, dev-5.next as 5.1.0)	53s
cs-stan / Coding Standard & Static Analysis	48s
	21m 36s

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