Replace Source §x Lazy in SICP JS in SICP JS 4.2.1 and 4.2.3 by the interpreter from 4.2.2

[martin-henz]

This will allow us to retire the languages Source §x Lazy including their documentation. To make the examples of 4.2.1 and 4.2.3 work in SICP JS, the repl module will come in handy.

[martin-henz]

Requires a new feature in the REPL module, see: source-academy/modules#317