Also update PDFMainBreakpoint after moving set_hammer_retq_breakpoints() to BreakpointManager

Remove finished TODO entry

- final names TBD
- TODO: GDB commands for highest per-arena and total mem use

- Commented out messages for memory allocations outside a parser context
- Commented out fallback for when a parser vtable can't be found in the dictionary, as that should be an error
- Added debug line printing the address that was not found in the vtable name->address dictionary

Extracting parser environment information will be done through the GDB Value API

- handle parser names being None in HammerParserBacktrace
- figured out subscripting, so the stringly typed code in the Env
classes can be replaced

Also removed an unused dict

Fixes:
- missing parenthesis in ActionEnv
- ord() instead of int() in ChEnv
- VTTypes() needs to be initialized in InitParserBreakpoint, to get the correct gdb frame. Also keep references in TopLevelParse

Dependencies between script files are kind of a mess at the moment

Backend support for parser hierarchy widget