Optimize list building patterns

[vyzo]

• Extracts with-list-builder into its own module so that it can be used more pervasively across the stdlib without carrying an implicit dependency to std/srfi/1.
• Optimizers list accumulation patterns across the stdlib; no more cons+reverse[!] loops, we either use with-list-builder or inline list accumulation, depending on what is more convenient and prudent.
• Optimizes for-collect go generate code with inline list accumulation.
• Optimizes iota to use inline list accumulation.