Implement support for BIP141 (Segregated Witness)

[kamikazebr]

Description:

I would like to suggest implementing support for BIP141 (Segregated Witness) in the BrBitcoin library. BIP141 introduces the "witness" structure in transactions, moving signature data outside the main transaction structure. This resolves the transaction malleability issue and increases transaction capacity per block without requiring a hard fork.

Benefits of implementation:

• Resolves transaction malleability, facilitating the development of second-layer solutions like the Lightning Network.
• Increases transaction capacity per block, improving network efficiency.

References:

• BIP141 - Segregated Witness
• Bitcoin Core documentation on SegWit

I believe that adding support for BIP141 will make BrBitcoin more robust and aligned with current best practices in the Bitcoin ecosystem.