Merge 'Fix sqlite_version() out of bound panics' from Diego Reis

#560
Changes to `translate_expr` function:
* [`core/translate/expr.rs`](diffhunk://#diff-
371865d5d7b8bcaed649413c687492e61e94f21387cd9b2c47d989a033888c8bL1558-
R1560): Changed the `amount` parameter in the `Insn::Copy` instruction
from `1` to `0`.
Enhancements to the testing framework:
* [`testing/scalar-functions.test`](diffhunk://#diff-
a046d58ab24eee8207f0ce3199f8d0a609edcef9c24b8ed7f242f7a60e6c1e61R812-
R815): Added a new test `do_execsql_test_regex` to validate that the
`sqlite_version` function returns a valid output.
* [`testing/tester.tcl`](diffhunk://#diff-
316cca92d85df3f78558cc3e60d7420c1fd19a23ecf2bbea534db93ab08ea3ecR29-
R45): Introduced a new procedure `do_execsql_test_regex` to support
regex-based validation of SQL outputs.

Closes #561

core/translate/expr.rs

@@ -1600,7 +1600,7 @@ pub fn translate_expr(
                             program.emit_insn(Insn::Copy {
                                 src_reg: output_register,
                                 dst_reg: target_register,
-                                amount: 1,
+                                amount: 0,
                             });
                             Ok(target_register)
                         }