feature: allow users to opt-in to release-candidate versions of kubo

**Is your feature request related to a problem? Please describe.**
Currently, desktop users only get a new version of kubo when we deploy a new version of ipfs-desktop. It would be nice if users could test out the new release candidate prior to that versions official release for a few reasons:

1. Users can ensure their workflows won't be interrupted by bugs in the new release
2. Devs can more easily test RC regressions prior to release

**Describe the solution you'd like**
I would like a way for users to opt-in to a dev channel and be notified and/or auto-updated (if dev-channel is enabled) to a release candidate of Kubo without us releasing an entirely new ipfs-desktop version.

One way we could do it is this:

### Opt-in flow
1. Prompt users who have no configuration set to opt in to devChannel for auto-releases
* Options are: disabled, enabled-manual, enabled-auto

### Update flow
1. If user is opted-in to devChannel
1. Query [dist](https://dist.ipfs.tech/#kubo) for RC versions
3. If RC version is available, use RC version instead of the version bundled with npmjs.com/go-ipfs

**Describe alternatives you've considered**
1. Not allowing easy testing of RC - current state

**Additional context**
Add any other context or screenshots about the feature request here.