fix: Principal JSON is compatible with @dfinity/utils jsonReviver helper

[krpeacock]

Description

@peterpeterparker brought up compatibility with @dfinity/utils in #766, and I agreed that we should use that standard for more concrete serialization. Instead of the string, will instead return an object,

{"__principal__":"ryjl3-tyaaa-aaaaa-aaaba-cai"}

matching a newly exported key, JSON_KEY_PRINCIPAL, and a returning a new type, JsonnablePrincipal.

Also extends the fromText and from constructors to support strings using the JSON-serialized principals

Fixes # (issue)

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide instructions so we can reproduce. Please also list any relevant details for your test configuration.

Checklist:

• My changes follow the guidelines in CONTRIBUTING.md.
• The title of this PR complies with Conventional Commits.
• I have edited the CHANGELOG accordingly.
• I have made corresponding changes to the documentation.

[github-actions]

size-limit report 📦

Path	Size
@dfinity/agent	87.43 KB (+0.06% 🔺)
@dfinity/candid	13.58 KB (+0.39% 🔺)
@dfinity/principal	5.2 KB (+0.93% 🔺)
@dfinity/auth-client	92.61 KB (+0.07% 🔺)
@dfinity/assets	90.01 KB (+0.06% 🔺)
@dfinity/identity	89.88 KB (+0.07% 🔺)
@dfinity/identity-secp256k1	232.59 KB (+0.04% 🔺)