Change Details

``` Generalize ConvertBits a bit to also be usable for the existing Base32 and Base64 convertions (rather than just for Bech32). ``` Backport of core PR11630. Depends on D5734. The key_io.cpp changes are not ported because they are segwit related, however some cashaddrenc.cpp and util_tests.cpp changes were required.

``` Generalize ConvertBits a bit to also be usable for the existing Base32 and Base64 convertions (rather than just for Bech32). ``` Backport of core [[https://github.com/bitcoin/bitcoin/pull/11630 | PR11630]]. Depends on D5734. The key_io.cpp changes are not ported because they are segwit related, however some cashaddrenc.cpp and util_tests.cpp changes were required.

``` Generalize ConvertBits a bit to also be usable for the existing Base32 and Base64 convertions (rather than just for Bech32). ``` Backport of core [[https://github.com/bitcoin/bitcoin/pull/11630 | PR11630]]. Depends on D5734. The key_io.cpp changes are not ported because they are segwit related, however some cashaddrenc.cpp and util_tests.cpp changes were required.