Add and document sqlpage.hmac function (#1033) #1761

Job	Run time
windows_test	5m 9s
compile_and_lint	2m 32s
test (mssql, mssql, mssql://root:[email protected]/sqlpage)	2m 16s
test (mysql, mysql, mysql://root:[email protected]/sqlpage)	2m 22s
docker_build (linux/arm64)	9m 7s
test (postgres, postgres, postgres://root:[email protected]/sqlpage)	2m 30s
docker_build (linux/amd64)	8m 17s
docker_build (linux/arm/v7)	8m 58s
test (odbc, postgres, Driver={PostgreSQL Unicode};Server=127.0.0.1;Port=5432;Database=sqlpage;UID...	3m 15s
docker_push	15s
	44m 41s

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