Fix hotreloading issues, clean up the CLI a bit

[jkelleyrtp]

• Fix Hot reloading updating wrong part inside a conditional expression #1995
• Fix Hot reloading doesn't send all edits on page reload #2074
• Fix Hot-reloading doesn't drop disconnected websocket connections #2075
• Fix Hotreloading doesn't hotreload let-bound rsx fragments #2076
• Fix Recovering from an error in hot reloading doesn't force a reload #1965
• Fix dioxus-cli + desktop asset dir resolution not working #2078
• Fix Allow running dioxus-cli without rustup installed #2052
• Fix If specified platform is found as feature in a crate, enable that feature #2080
• Fix bug: Embedded hot-reload doesn't seem to work #1914

Fixes some untracked issues:

• hot reloading currently doesn't update on reloads
• latent websocket connections aren't dropped
• hot reload file map technically only allows one template per pathbuf (file)
• assets weren't being reloaded
• css is now hot reloaded using query-segment invalidation