984d72ec65 Return the script type from Solver (Ben Woosley)
Pull request description:
Because false is synonymous with TX_NONSTANDARD, this conveys the same
information and makes the handling explicitly based on script type,
simplifying each call site.
Prior to this change it was common for the return value to be ignored, or for the
return value and TX_NONSTANDARD to be redundantly handled.
Tree-SHA512: 31864f856b8cb75f4b782d12678070e8b1cfe9665c6f57cfb25e7ac8bcea8a22f9a78d7c8cf0101c841f2a612400666fb91798bffe88de856e98b873703b0965