API: Rename disablepp and introduce disabletidy
- Rename disablepp to disablelimitreport, since it does not disable the preprocessor (which is what PP stands for in "NewPP").
- Introduce new option "disabletidy" for T89331
- Suppress the use of the parser cache when options are specified that affect the output but are not in ParserOptions::optionsHash(). This was already broken, but the damage was fairly limited since the options rarely caused user-visible changes. It would break very badly if I use the disabletidy option for what I am intending.