Requirements for an outer parser

[gtrepta]

For pyk to do outer parsing when invoked by pyk kompile, there are a few major steps it needs to perform:

• Add source location information to outer parsing #4180
• Parse files included with requires clauses
• Parse and add prelude.md to the definition unless --no-prelude is passed
• Resolve the main/syntax module names.
• Convert K language items to KAST items #4259
• Convert AST to KAst #4260

This should be the absolute minimum that needs to be done by pyk. There are some other checks and transformations that get done in the java outer parsing. It may be possible to move these further down the compilation pipeline. See #4131