x86_64 Bitcoin Software Installed on M1s

At time of release for 1.0.2, the arm64 version of `bitcoind` fails on our M1 test mac with an "Error 9". As a result, the x86_64 version is used for both installations.

This should certainly be rechecked when a new version of Bitcoin is released. If the arm64 `bitcoind` is now working on an M1, then the architecture check in Standalone script can be uncommented to automatically use it. There may also need to be a change in the Helpers Defaults file, which has its own variable for the architecture-named tar file (but it's unclear if it's used).

Start with the architecture check in the Standalone script and the architecture-named tar-file variable in the Helpers Defaults file. Recheck whether the arm64 bitcoind works on an M1 with a newer Bitcoin release, then verify that the installation selects the working architecture and that the resulting installation completes successfully.

Written by the indexing model from the issue text.