Consolidate all uses of the fast range mapping technique in util/fastrange.h
Summary:
Several places in the codebase use the fast range mapping technique described in https://lemire.me/blog/2016/06/27/a-fast-alternative-to-the-modulo-reduction/, some for 32-bit ranges, some for 64-bit ones. Move all of these to util/fastrange.h, and give them a consistent name.
Backport of core#23994.
Test Plan:
ninja all check-all ninja bitcoin-fuzzers
Reviewers: #bitcoin_abc, PiRK
Reviewed By: #bitcoin_abc, PiRK
Subscribers: PiRK
Differential Revision: https://reviews.bitcoinabc.org/D14394