[squashme] Fix macos dmg location in CI

[squashme] sha256sum not present in macos userland

macOS deploy: use the new plistlib API

[squashme] More macos CI fixes

[smly] Make GetVersionForAlgo implicitly return BLOCK_VERSION_SCRYPT if no match

[squashme] Add MacOs build step to CI

[smly] Add premine subsidy amount as param field, fix subsidy halving tests

[smly] Add github actions workflows with bdb4.8 compilation

[smly] Fix test_bitcoin and bloom filter unit test suites

[smly] Change transaction versions to 1

[smly] Change default address to LEGACY

[smly] Disable block version checks for bips 34 66 and 65

[smly] Add multialgo methods to chain.cpp

[squashme] pow.cpp fix

[smly] Add multialgo methods to block primitive