Add better error handling

[BlathanAevon]

TypeScript Improvements:

Added proper interface definition for key pair results
Made the class methods more strongly typed
Removed default exports in favor of named exports

Error Handling:

Added try-catch blocks to all methods
Included meaningful error messages
Proper error propagation

Performance Optimizations:

Cached TextEncoder as a static class property
Reduced buffer conversions where possible
Used array spread instead of concatenation
Simplified the biscuit token creation with reduce()

Code Organization:

Converted to a proper class structure
Added JSDoc comments for better documentation
Consistent method naming (removed camelCase prefix)
Made methods public for better TypeScript support

Buffer Handling:

Simplified buffer conversions
Removed redundant buffer creation
More efficient byte array handling

General Improvements:

Removed redundant variable declarations
Simplified control flows
More consistent return types
Better separation of concerns

[chilaraiSxt]

Thanks for the PR. Please fix the below errors and merge with main

yarn run build

warning ../../package.json: No license field
$ tsc  && node --experimental-wasm-modules  ./dist/src/index.js
src/authorization/authorization.ts:28:25 - error TS2769: No overload matches this call.
  Overload 1 of 3, '(callbackfn: (previousValue: BiscuitCapabilities, currentValue: BiscuitCapabilities, currentIndex: number, array: BiscuitCapabilities[]) => BiscuitCapabilities, initialValue: BiscuitCapabilities): BiscuitCapabilities', gave the following error.
    Argument of type '(builder: BiscuitBuilder, cap: BiscuitCapabilities) => void' is not assignable to parameter of type '(previousValue: BiscuitCapabilities, currentValue: BiscuitCapabilities, currentIndex: number, array: BiscuitCapabilities[]) => BiscuitCapabilities'.
      Types of parameters 'builder' and 'previousValue' are incompatible.
        Type 'BiscuitCapabilities' is missing the following properties from type 'BiscuitBuilder': free, build, merge, addFact, and 4 more.
  Overload 2 of 3, '(callbackfn: (previousValue: BiscuitBuilder, currentValue: BiscuitCapabilities, currentIndex: number, array: BiscuitCapabilities[]) => BiscuitBuilder, initialValue: BiscuitBuilder): BiscuitBuilder', gave the following error.
    Argument of type '(builder: BiscuitBuilder, cap: BiscuitCapabilities) => void' is not assignable to parameter of type '(previousValue: BiscuitBuilder, currentValue: BiscuitCapabilities, currentIndex: number, array: BiscuitCapabilities[]) => BiscuitBuilder'.
      Type 'void' is not assignable to type 'BiscuitBuilder'.

28                 .reduce((builder, cap) => {
                           ~~~~~~~~~~~~~~~~~~~


src/authorization/authorization.ts:32:18 - error TS2339: Property 'build' does not exist on type 'BiscuitCapabilities'.

32                 .build(PrivateKey.fromString(privKey))
                    ~~~~~

src/authorization/authorization.ts:54:18 - error TS2339: Property 'build' does not exist on type 'void'.

54                 .build(PrivateKey.fromString(privKey))
                    ~~~~~

src/index.ts:2:8 - error TS2613: Module '"/Users/chilarai/Projects/SxT-NodeJS-SDK/src/authorization/authorization"' has no default export. Did you mean to use 'import { Authorization } from "/Users/chilarai/Projects/SxT-NodeJS-SDK/src/authorization/authorization"' instead?

2 import Authorization from "./authorization/authorization.js";
         ~~~~~~~~~~~~~


Found 4 errors in 2 files.

Errors  Files
     3  src/authorization/authorization.ts:28
     1  src/index.ts:2
error Command failed with exit code 2.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.

[BlathanAevon]

Please checkout the latest update

[chilaraiSxt]

Please checkout the latest update

Hey, please fix the errors. Once the errors are fixed please run npm run build or yarn run build to see if it compiles successfully
https://github.com/spaceandtimelabs/SxT-NodeJS-SDK/actions/runs/13307645493/job/37462026286?pr=15