Return 400 for invalid UTF-8 multipart fields #2275

Job	Run time
docker_build (linux/arm64, minimal)	5m 50s
docker_build (linux/arm/v7, minimal)	5m 14s
compile_and_lint	1m 47s
docker_build (linux/amd64, minimal)	5m 14s
windows_test	2m 28s
test (mssql, mssql, mssql://root:Password123!@127.0.0.1/sqlpage)	2m 16s
docker_build (linux/arm64, duckdb)	5m 52s
test (mysql, mysql, mysql://root:Password123!@127.0.0.1/sqlpage)	1m 50s
test (odbc, postgres, Driver=PostgreSQL Unicode;Server=127.0.0.1;Port=5432;Database=sqlpage;UID=r...	2m 57s
docker_build (linux/amd64, duckdb)	5m 8s
test (oracle, oracle, Driver=Oracle 21 ODBC driver;Dbq=//127.0.0.1:1521/FREEPDB1;Uid=root;Pwd=Pas...	3m 10s
test (postgres, postgres, postgres://root:Password123!@127.0.0.1/sqlpage)	2m 22s
docker_push	-1s
	44m 7s

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