* Related to #1547: use `dioxus-cli` within a workspace
Although the `dx` CLI allows to specify a package name to chose from workspace members,
it does not support workspace members specified as glob-wildcards.
Neither it respects the effective package name, specified in the crate's `Cargo.toml`.
This PR addresses that issue:
- upon `dx build ...`, if the `--bin` CLI-argument is provided, treat the current dir as a workspace;
- search through the workspace's `members`: resolve each of them with `glob`;
- assume that any workspace member has a `Cargo.toml` in it (cargo does it, so it's okay);
- read said manifest, and check the package name in it;
- if found — there we have our sought package.
* Use cargo-metadata to find out the workspace structure
* glob is unused
* fix(serve): provide a clear error with pathless proxy URLs
Without this, `dx serve` panics with this message:
```
Paths must start with a `/`. Use "/" for
root routes
```
That's not very clear. Instead, we can detect this situation and provide a better error message:
```
Error: 🚫 Serving project failed: Failed to establish proxy: Proxy backend URL must have a non-empty path, e.g. http://localhost:8080/api instead of http://localhost:8080
```
* docs(config): correct format for `web.proxy`
Raman Hafiyatulin