Metadata TZIP-16: add warning on metadata URI/JSON when compiling storage (Michelson)

Motivation and Context

Related Issue: #1788 (closed).

Description

This MR adds warnings checking the following:

• Checks that %metadata has a key "".
• That the value corresponding to the key "" above is a sha256, http, https, ipfs or tezos-storage URI.
• In case the above is a tezos-storage without host, then the key pointed by the path also exists in %metadata.
• In case the above is an URL, the file could be downloaded using --allow-json-download.
• The pointed document/value is valid JSON (including well typed views).

This is an alternative to !2703 (closed) , in which we do not have to modify testing framework and analyze directly the storage as Michelson.

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 checks for metadata TZIP-16 are included.

This is a breaking change, as now metadata type compliance is disabled by default and --no-metadata-check flag no longer exists.

To verify TZIP-16 compliance, pass the flag --verify-tzip16 to compilation sub-commands (particularly compile storage).

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).