Make sure errors encountered while initializing extensions such as FTS4

get reported out from sqlite3_open().  This fixes a bug introduced by
check-in [9d347f547e7ba9].  Also remove lots of forgotten "breakpoint"
commands left in test scripts over the years.

FossilOrigin-Name: ca3fdfd41961d8d3d1e39d20dc628e8a95dabb2f