[JsLIGO] Refactoring of the CST and grammar

Motivation and Context

Description

#1269 (closed)

Other changes:

• true, false become keywords (and thus stdlib is updated).
• new support for pattern matching
• do { ... } expressions
• Added 0nat and 0mutez literals
• Added bitwise operators
• Added access to properties with integers and strings
• More patterns

Component

• compiler
• website
• webide
• vscode-plugin
• debugger

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Performance improvement (non-breaking change that improves performance)
• None (change with no changelog)

Changelog

New pattern matching in JsLIGO

It follows a variant of tc39 proposal pattern matching.

E.g.

match (action) {
    when(Add(n)): n;
    when(Sub(n)): -n;
  }

Checklist:

• If a new syntax has been introduced, put a message on slack ligo-lsp
• Changes follow the existing coding style (use dune @fmt to check).
• Tests for the changes have been added (for bug fixes / feature).
• Documentation has been updated.
• Changelog description has been added (if appropriate).
• Start titles under ## Changelog section with #### (if appropriate).
• There is no image or uploaded file in changelog
• Examples in changed behaviour have been added to the changelog (for breaking change / feature).