fix(developer): lm compiler handle missing line no in errors

Fixes #8443.

Will cherry-pick to stable-16.0.

The regex for matching error messages has an optional section for
the file/line detail (line 54):

```regex
^(?:(.+) \((\d+)\): )?<snip>
```

The code that parses the results did not account for this being
optional, which would cause a crash if the error message did not include
this information.

developer/src/common/delphi/lexicalmodels/Keyman.Developer.System.LexicalModelCompile.pas

@@ -61,7 +61,7 @@ begin
       if m.Success then
       begin
         msgFilename := m.Groups[1].Value;
-        msgLine := StrToInt(m.Groups[2].Value);
+        msgLine := StrToIntDef(m.Groups[2].Value, 0);
         msgType := m.Groups[3].Value;
         msgCode := StrToInt('$'+m.Groups[4].Value);
         msgText := m.Groups[5].Value;