Migrate from @noble/secp256k1 to @noble/curves for enhanced security (#10)

- Dependency Migration: Replaced `@noble/secp256k1` with `@noble/curves`, enhancing security and maintainability as recommended by @paulmillr. Updated internal implementations to utilize `@noble/curves` APIs while preserving the same external API for users.
- Behavior Update: Updated the `signSchnorr` function to remove default zero-filled auxiliary randomness (`e`) initialization. It now defaults to secure random values if not explicitly provided, improving compliance with best practices.
- Documentation Update: Revised the README to:
  - Reflect the migration to noble-curves.
  - Document the `signSchnorr` behavior change, highlighting the deviation from `bitcoinjs/tiny-secp256k1` for auxiliary randomness and linking relevant discussions for context.

Version Bump: Incremented the version to `1.2.0` to indicate the significant internal changes while maintaining external compatibility.

Testing: All existing tests have been updated and pass successfully with the new dependency and refactored implementations.

Author: landabaso

README.md

@@ -9,7 +9,7 @@ Test this: https://github.com/spsina/bip47
 
 # Secp256k1
 
-@bitcoinerlab/secp256k1 is a Javascript library for performing elliptic curve operations on the secp256k1 curve. It is designed to integrate into the [BitcoinJS](https://github.com/bitcoinjs) and [BitcoinerLAB](https://bitcoinerlab.com) ecosystems and uses the audited [noble-secp256k1 library](https://github.com/paulmillr/noble-secp256k1), created by [Paul Miller](https://paulmillr.com/noble/).
+@bitcoinerlab/secp256k1 is a Javascript library for performing elliptic curve operations on the secp256k1 curve. It is designed to integrate into the [BitcoinJS](https://github.com/bitcoinjs) and [BitcoinerLAB](https://bitcoinerlab.com) ecosystems and uses the audited [noble-curves library](https://github.com/paulmillr/noble-curves), created by [Paul Miller](https://paulmillr.com/noble/).
 
  This library is compatible with environments that do not support WebAssembly, such as React Native.
 
@@ -34,7 +34,9 @@ npm install @bitcoinerlab/secp256k1
 
 This implementation follows the tiny-secp256k1 API. Please refer to [tiny-secp256k1](https://github.com/bitcoinjs/tiny-secp256k1#documentation) for documentation on the methods.
 
-This method is not yet implemented: `xOnlyPointAddTweakCheck`. It is not used in ecpair or bip32, though.
+- **`xOnlyPointAddTweakCheck`**: This method is not yet implemented. It is not used in `ecpair` or `bip32`.
+
+- **`signSchnorr`**: Starting from version 1.2.0, this function deviates from the exact behavior mapping with [`bitcoinjs/tiny-secp256k1`](https://github.com/bitcoinjs/tiny-secp256k1) and no longer initializes the auxiliary random data parameter (`e`) to a zero-filled array by default. Instead, it requires the caller to explicitly provide randomness if desired. If omitted, the underlying implementation uses cryptographically secure randomness (through `crypto.getRandomValues`). For more details on this change, see the discussion [here](https://github.com/bitcoinerlab/secp256k1/pull/10#discussion_r1876541974) and the conclusions [here](https://github.com/bitcoinerlab/secp256k1/pull/10#issuecomment-2537916286).
 
 ### Examples