bug(developer): index() works without a comma between parameters in kmcmplib compiler

[markcsinclair]

Describe the bug

If the phrase index(b 4) is used (where b is a valid store), the compiler treats it as if a comma was present i.e. index(b,4) rather than raising an error.

Related issues

#11814 also highlights problems with index()

Keyman apps

• [ ] Keyman for Android
• [ ] Keyman for iPhone and iPad
• [ ] Keyman for Linux
• [ ] Keyman for macOS
• [ ] Keyman for Windows
• [X] Keyman Developer
• [ ] KeymanWeb
• [ ] Other - give details at bottom of form