Some projects use different system and arch names in their assets.
Sometimes due to convention or differeing tools and systems. For
example, on macOS 13.6, Python will return the system as `Darwin`.
However, some release assets will be named `macOS` or `macos`. Similarly
`arm64` and `aarch64` are used interchangeably.
This patch adds a few lists of synonymous values such that
release-gitter can make an attempt at matching the intended binary.
These lists of synonyms can be expanded to be more complete as time goes
on.
These synonyms are only used if there is no user provided mapping. In
the case that any user provided mapping exists, the map will be the
sole source of truth. Eg. If you provide a map for `Windows=>windows`,
no other values will be mapped and we won't assume that `Darwin=>macos`
anymore.