fix(sdk-core): use newWalletPassphrase in processAcceptShare for bulk operations

Fixed processAcceptShare to correctly use newWalletPassphrase when provided
for both keychainOverrideRequired and userMultiKeyRotationRequired cases in
bulk wallet share operations. Updated validation to accept either
newWalletPassphrase or userLoginPassword for userMultiKeyRotationRequired
shares.

Added comprehensive tests to verify:
- Bulk accept share with userMultiKeyRotationRequired and newWalletPassphrase
- Bulk accept share with keychainOverrideRequired and newWalletPassphrase
- Error handling when neither password is provided
- Correct usage of newWalletPassphrase vs userLoginPassword

Fixed existing keychainOverrideRequired tests to use correct API endpoints
(ofc instead of tbtc) and made nock matchers more flexible to handle dynamic
signatures and payloads.

WP-6769

TICKET: WP-6769

Author: zahin-mohammad