This change shaves ~20 MB off the download size by only copying over the
wavesrv binary that is relevant for whichever architecture we're
currently packaging. This is only relevant for macOS at the moment,
though it can also apply to Windows when we get multi-arch builds
working.
This required renaming our Go binaries from .amd64 to .x64 to comply
with electron-builder's naming conventions.
With this PR, Electron will generate a new authorization key that the Go
backend will look for in any incoming requests. The Electron backend
will inject this header with all requests to the backend to ensure no
additional work is required on the frontend.
This also adds a `fetchutil` abstraction that will use the Electron
`net` module when calls are made from the Electron backend to the Go
backend. When using the `node:fetch` module, Electron can't inject
headers to requests. The Electron `net` module is also faster than the
Node module.
This also breaks out platform functions in emain into their own file so
other emain modules can import them.
