Add importprivkeys RPC

This is particularly noted to be a common issue within the Namecoin community. The current limitations surrounding the import of private keys into these wallets are highlighted as an unnecessary barrier for average users, which has led to the development of a solution aimed at simplifying this process.

A Python-based tool named Core-Wallet-Migration-Tools has been developed and made available on GitHub (Core-Wallet-Migration-Tools) to assist users in migrating their private keys (both legacy and Bech32/SegWit) into Bitcoin Core descriptor wallets. Despite this workaround, there's an identified need for a more integrated solution within the Bitcoin Core itself to streamline this process further.

The proposal put forth suggests the introduction of an 'importprivkeys' RPC call specifically designed for descriptor wallets, distinct from the existing 'importprivkey' call used for legacy wallets. This proposed RPC command aims to facilitate the importation of Wallet Import Format (WIF) keys directly into descriptor wallets, thereby significantly easing the user experience in managing private keys within these modern wallet structures.

Further insights into this proposal, including its technical specifics and justification, can be found through a detailed document available on Gist (Proposal: Add importprivkeys RPC). This initiative underlines the ongoing efforts within the Bitcoin development community to enhance accessibility, usability, and the overall user experience in managing digital assets securely and efficiently.