Wisefool769/typescript fixes

[wisefool769]

Description

Improves typing to enable library to be used in projects with a stricter TSConfig. Also makes the TSConfig stricter in this repo so this doesn't drift in the future. Some of these were preventing me from using cdp-sdk in my project without a patch.

Closes #410 and #345

Tests

  # Standard TypeScript check:
  npx tsc --noEmit

  # Strict TypeScript check (the key one that caught all the original errors):
  npx tsc --noEmit --noImplicitAny --noImplicitReturns --noImplicitThis

  # Code Quality Tests

  # ESLint (including Prettier formatting):
  pnpm lint

  # Auto-fix linting issues:
  pnpm lint:fix

Checklist

A couple of things to include in your PR for completeness:

• Updated the typescript README if relevant (Not applicable)
• Updated the python README if relevant (Not applicable)
• Added a changelog entry
• Added e2e tests if introducing new functionality (Not Applicable)

[cb-heimdall]

🟡 Heimdall Review Status

Requirement	Status	More Info
Reviews	🟡 0/1	Denominator calculation Show calculation 1 if user is bot 0 1 if user is external 0 2 if repo is sensitive 0 From .codeflow.yml 1 Additional review requirements Show calculation Max 0 0 From CODEOWNERS 0 Global minimum 0 Max 1 1 1 if commit is unverified 0 Sum 1