spacetime init rewrite (#3366)

This is a draft of the new functionality for `spacetime init`. In order
to run it with built-in templates you have to set the path to the config
file:

```
export SPACETIMEDB_CLI_TEMPLATES_FILE=crates/cli/.init-templates.json
```

In the future it will fetch the list from GH.

A few notes:

* the previous functionality of `spacetime init` does not work at the
moment
* the code needs a bit more cleanup and tests before merging
* there is a bit of a mix in how we generate empty server and client
projects. For Rust we use the existing way of generating. For TypeScript
we clone an empty project from the repo. I wanted to play with both ways
of doing things, and I'm still not sure which is better. Generation in
Rust means that the generated code will match the CLI version and not
necessarily whatever is in Git. On the other hand, for the builtin
templates we will be fetching the newest version from GH, which I guess
might also not what we want, ie. we probably want only stable templates.
More discussion is needed here
* we use `spacetimedb` directory for the server files
* I don't particularly like the inability to disable interactive mode
easily. We discussed disabling it by default if all of the required
arguments are passed, but I don't think it's feature proof. For example,
if someone relies on a non-interactive mode, and we add a new required
argument, instead of printing a message `missing --foo`, we will
automatically launch interactive mode, which is harder to debug. That's
why I think I'd prefer to implement `--non-interactive` argument
* it's kind of hard to keep the legacy behaviour. If you don't pass any
arguments, we go into interactive mode. In the legacy version, we would
print required arguments. If someone passes `--lang` or `--project-path`
explicitly, I guess we could run the legacy workflow, but not sure if
it's worth it, as the command was marked as unstable anyway
* the project path defaults to the project name, but I think we should
probably replace change whitespaces to dashes, or at least ask for the
project path with the project name being the default (or both)

---------

Signed-off-by: Tyler Cloutier <[email protected]>
Signed-off-by: John Detter <[email protected]>
Co-authored-by: = <[email protected]>
Co-authored-by: Tyler Cloutier <[email protected]>
Co-authored-by: Tyler Cloutier <[email protected]>
Co-authored-by: John Detter <[email protected]>

Author: 3 people

examples~/quickstart-chat/client/Program.cs

@@ -34,18 +34,18 @@ void Main()
 }
 
 /// The URI of the SpacetimeDB instance hosting our chat module.
-const string HOST = "http://localhost:3000";
+string HOST = Environment.GetEnvironmentVariable("SPACETIMEDB_HOST") ?? "http://localhost:3000";
 
 /// The module name we chose when we published our module.
-const string DBNAME = "quickstart-chat";
+string DB_NAME = Environment.GetEnvironmentVariable("SPACETIMEDB_DB_NAME") ?? "quickstart-chat";
 
 /// Load credentials from a file and connect to the database.
 DbConnection ConnectToDB()
 {
     DbConnection? conn = null;
     conn = DbConnection.Builder()
         .WithUri(HOST)
-        .WithModuleName(DBNAME)
+        .WithModuleName(DB_NAME)
         .WithToken(AuthToken.Token)
         .OnConnect(OnConnected)
         .OnConnectError(OnConnectError)

examples~/quickstart-chat/client/client.csproj

@@ -15,4 +15,8 @@
     <ProjectReference Include="../../../SpacetimeDB.ClientSDK.csproj" />
   </ItemGroup>
 
+  <ItemGroup>
+    <Compile Remove="spacetimedb/**" />
+  </ItemGroup>
+
 </Project>