`SLICE` instruction in testing framework's interpreter

Motivation and Context

We have a discrepancy between testing framework's interpretation of Bytes.sub/String.sub and that of Michelson's interpreter.

It can be witnessed with this example:

$ ligo compile expression cameligo "Bytes.sub 5n 0n (0xf0f9c27422 : bytes)"
An error occurred while evaluating an expression: "SLICE"
$ cat test.mligo 
let test = Bytes.sub 5n 0n (0xf0f9c27422 : bytes)
$ ligo run test test.mligo
Everything at the top-level was executed. 
- test exited with value 0x.

Also, for String.sub, we have:

$ cat test.mligo
let test = String.sub 5n 10n "hola"
$ ligo run test test.mligo 
An internal error ocurred. Please, contact the developers.
(Invalid_argument "pos + len past end: 5 + 10 > 4").

We should not reveal this kind of error.

Description

This MR fixes the issue by guarding sub in the interpreter with the correct checks.

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

Checklist:

• 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).
• Examples in changed behaviour have been added to the changelog (for breaking change / feature).