Off by one error in stack traces

[orpuente-MS]

Describe the bug

There is an off by one error in the stack trace line when logging a runtime error.

To Reproduce

Paste this code in the editor and run it. Then look at the stack trace.

function Main() : Unit {
    fail "line 2";
}

Expected behavior

The stack trace should report the failure at line 2, but reports it at line 1.

[orpuente-MS]

A good place to start looking is at the UTF encoding being used in the get_position function in source/compiler/qsc/src/interpret/debug.rs.

[minestarks]

Note to Copilot: This is for running via the code lens command in VS Code. Output is shown in the Debug Console.