Prevent invalid js generation for module names with an apostrophe: - #3602

Formerly, the purescript code

module Foo' where
foo = "foo"

module Bar where
import Foo'

would be parsed without error but would generate the following invalid javascript:

var Foo' = require("../Foo'/index.js");

The present commit prevents this error in two ways:

1. requiring that module and qualifier names comprise alphanumeric characters only;
   (I've seen some past discord among ps developers about this restriction,
   but it seems the safest choice and code currently in Parser/Lexer.hs (specifically, 'validUName')
   suggests that's the present naming policy.)
2. applying 'identCharToText' to ModuleNames
   to ensure that the rendered javascript variable names contain no invalid chars,
   should module-naming conventions ever change.