fix: typescript definitions

[markin-io]

Issue being fixed or feature implemented

Fixed issue with the type system export and addressed some typings bugs

What was done?

• Fixed bugs in existing typings systems
• Made types accessible in both *.ts and *.d.ts (Got rid of export declare module and exported types directly from the root index.d.ts)
• Added basic tests for exported type definitions

How Has This Been Tested?

• CI
• Tested imports in wallet-lib's *.d.ts definitions
• Tested imports in SDK TS code

Breaking Changes

Checklist:

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have added or updated relevant unit/integration/functional/e2e tests
• I have made corresponding changes to the documentation

[jawid-h]

Looks okay to me 👍

[shumkov]

👍