Dictu stdlib

[Jason2605]

Well detailed description of the change :

This PR overhauls the stdlib and how optional modules are imported into Dictu. This allows us to execute Dictu at runtime when importing modules within the stdlib (which crucially allows us to "self host" the stdlib).

Along with this two new modules are being added:

• UnitTest
  • This module will provide a nicer way to create unit tests over the current version where we are stuck with assert-ing code.
• Inspect
  • This will allow some introspection into the VM state.

Resolves: #431

Type of change:

• New feature

Housekeeping

• Tests have been updated to reflect the changes done within this PR (if applicable).

• Documentation has been updated to reflect the changes done within this PR (if applicable).