nightly builds of the CLI

## Feature Request

It would be nice if we could install nightly builds of the CLI without having to go through `cargo install`. Ideally we can just use the cargo binstall infrastructure we have, but with an optional `--branch` flag to install from a specific branch.

## Implement Suggestion

Github lets you upload artifacts from PR runs - it should be simple enough to upload our nightly CLI builds and then wire them up to `dioxus.dev/install.sh`.