Add function for stringifying wrapper types as unwrapped, serializable types

[soerenbf]

Purpose

Unwrap types to a representation of the inner value, to make it easier to stringify structures using the newly added types into something sensible (f.x. for http requests).

Types that already had toJSON functions on them are kept as is.

Changes

• Add toJSON functions where needed.

Checklist

• My code follows the style of this project.
• The code compiles without warnings.
• I have performed a self-review of the changes.
• I have documented my code, in particular the intent of the
  hard-to-understand areas.
• (If necessary) I have updated the CHANGELOG.

[soerenbf]

Kept as draft until it's been verified as compatible in Concordium/concordium-dapp-libraries#51

[shjortConcordium]

These changes do break with the browser wallet, using this with wCCD, gives me
Error: The given transaction is not valid due to: TypeError: Cannot read properties of undefined (reading 'split').
I'll check wallet connect tomorrow.

[soerenbf]

These changes do break with the browser wallet, using this with wCCD, gives me Error: The given transaction is not valid due to: TypeError: Cannot read properties of undefined (reading 'split'). I'll check wallet connect tomorrow.

Upon checking again it seems you're right.. Will need to figure out an alternative