test: Add pure Python RIPEMD-160 and use it instead of OpenSSL

Summary:
OpenSSL 3 removed ripemd160, see openssl/openssl#16994

Thus, the functional tests fail on systems with OpenSSL 3.

This is a backport of core#23716

Test Plan: ninja check-functional-extended

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Differential Revision: https://reviews.bitcoinabc.org/D11413