Debugger: Command prompt doesn't parse breakpoint command

[zaddach]

Describe the bug
I'm trying to add a breakpoint on the command prompt of the debugger using the b Rule or breakpoint Rule syntax. The debugger is responding with Unrecognized command: breakpoint Rule; use h for help.

To Reproduce

• With the pest_debugger.exe compiled from the master branch
• Run the debugger with a grammar and some input
• Attempt to add a breakpoint with b Rule ("Rule" must exist as a rule in the grammar)
• The debugger will respond with Unrecognized command: breakpoint Rule; use h for help.

Expected behavior
I'd expect the debugger to add the breakpoint to the breakpoint list (inspectable with l)

Additional context
Breakpoint commands are parsed here. I don't get how "breakpoint".starts_with("b Rule") should evaluate to true.