Standardize the error messages generated by constraint failures to a format

of "$TYPE constraint failed: $DETAIL".  This involves many changes to the
expected output of test cases.

FossilOrigin-Name: 54b221929744b1bcdbcc2030fef2e510618afd41

test/without_rowid1.test

@@ -52,7 +52,7 @@ do_test without_rowid1-1.21 {
   catchsql {
     INSERT INTO t1 VALUES('dynamic','phone','flipper','harvard');
   }
-} {1 {PRIMARY KEY must be unique}}
+} {1 {UNIQUE constraint failed: t1.c, t1.a}}
 
 # REPLACE INTO works, however.
 #