Introduce a Shuffle for FastRandomContext and use it in wallet and coinselection

Summary: This is a partial backport of Core PR14624 : https://github.com/bitcoin/bitcoin/pull/14624/commits/3db746beb407f7cdd9cd6a605a195bef1254b4c0

Test Plan:

make check

Reviewers: #bitcoin_abc, markblundeberg

Reviewed By: #bitcoin_abc, markblundeberg

Differential Revision: https://reviews.bitcoinabc.org/D3449