Make URL and POST parameters immutable #1962

Job	Run time
compile_and_lint	1m 29s
docker_build (linux/arm/v7)	5m 17s
windows_test	3m 13s
docker_build (linux/amd64)	4m 55s
docker_build (linux/arm64)	5m 42s
test (odbc, postgres, Driver=PostgreSQL Unicode;Server=127.0.0.1;Port=5432;Database=sqlpage;UID=r...	1m 46s
test (postgres, postgres, postgres://root:Password123!@127.0.0.1/sqlpage)	1m 32s
test (mssql, mssql, mssql://root:Password123!@127.0.0.1/sqlpage)	1m 27s
test (mysql, mysql, mysql://root:Password123!@127.0.0.1/sqlpage)	1m 23s
docker_push	0s
	26m 44s

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