Fix libmysql test cases (#7097)

Fixed test cases for: mysqli_stmt_execute_bind_libmysql, bug77935, fetch_column, and some others that failed on libmysql

Port skipif.inc files to EXTENSIONS

Deprecate unused mysqli constants (#6850)

Deprecated:
MYSQLI_SERVER_QUERY_NO_GOOD_INDEX_USED
MYSQLI_SERVER_QUERY_NO_INDEX_USED
MYSQLI_SERVER_QUERY_WAS_SLOW
MYSQLI_SERVER_PS_O

Deprecate unused mysqli constants (#6850)

Deprecated:
MYSQLI_SERVER_QUERY_NO_GOOD_INDEX_USED
MYSQLI_SERVER_QUERY_NO_INDEX_USED
MYSQLI_SERVER_QUERY_WAS_SLOW
MYSQLI_SERVER_PS_OUT_PARAMS
MYSQLI_DATA_TRUNCATED
MYSQLI_NO_DATA

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