Feature/lit 2961 auth unification breaking remove existing authsigs

[Ansonhkg]

Description

• Removed authSig as an option to pass in to endpoint functions eg. pkpSign executeJs and signSessionKey
• Extracted out all parser, helper, transcompiler functions in the pkpSign and executeJs to a dedicated helpers folder with isolated unit tests
• Removing getXXPromiseShares methods in the LitNodeClient & its interface, and replacing it with a generic generatePromise instead. See lit-node-client-nodejs.ts
• Better types for IOs

Note

The commit history is a bit overlapping with other PRs because I need the tests and some other features, please review from the commit below onward (or I just open a new PR and cherry pick the commits if that's better, lmk.)

• 35ede36

Type of change

• [x] Bug fix (non-breaking change which fixes an issue)
• [x] New feature (non-breaking change which adds functionality)
• [x] Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [x] This change requires a documentation update

How Has This Been Tested?

• [x] Unit test (Jest)
• [x] E2E test (Tinny)

Checklist:

• [x] My code follows the style guidelines of this project
• [ ] I have performed a self-review of my code
• [x] I have commented my code, particularly in hard-to-understand areas
• [ ] I have made corresponding changes to the documentation
• [x] My changes generate no new warnings
• [x] I have added tests that prove my fix is effective or that my feature works
• [x] New and existing unit tests pass locally with my changes
• [ ] Any dependent changes have been merged and published in downstream modules

[joshLong145]

@Ansonhkg this looks awesome! Thinking to get ready for this merger we should make a release/6.0.0 branch where we can start merging this work into and doing test runs. WDYT? we then could start merging #444 #436

[DashKash54]

@Ansonhkg this looks awesome! Thinking to get ready for this merger we should make a release/6.0.0 branch where we can start merging this work into and doing test runs. WDYT? we then could start merging #444 #436

I think we should merge https://github.com/LIT-Protocol/js-sdk/pull/435 instead of these sub-branches

[DashKash54]

@Ansonhkg Still a bunch of unresolved comments. Can you please respond and resolve those, thanks