CLI - Better module language inference

[bfops]

Description of Changes

We used to assume a project was a rust project if it had a Cargo.toml, and otherwise assume that it's a .NET project. Now we do something slightly smarter, where we only assume it's a .NET project if there's a *.csproj file (and error otherwise).

Fixes #2136 .

API and ABI breaking changes

No, not for projects that are in any format we expect.

Expected complexity level and risk

1

Testing

• No Cargo.toml or *.csproj causes an error:

$ mkdir test-project && cd test-project
$ spacetimedb-cli publish -s local foo
Error: Could not detect the language of the module. Are you in a SpacetimeDB project directory?

• A .csproj file causes the project to be treated as .NET

$ mkdir test-project && cd test-project
$ touch Foo.csproj
$ spacetimedb-cli publish -s local foo
MSBuild version 17.8.5+b5265ef37 for .NET
/mnt/nutera/work/foo/Foo.csproj : error MSB4025: The project file could not be loaded. Root element is missing.
Error: command ["dotnet", "publish", "-c", "Release", "-v", "quiet"] exited with code 1

• A Cargo.toml causes the project to be treated as Rust:

$ mkdir test-project && cd test-project
$ touch Cargo.toml && mkdir src
$ spacetimedb-cli publish -s local foo
error: failed to parse manifest at `/mnt/nutera/work/foo/Cargo.toml`

Caused by:
  manifest is missing either a `[package]` or a `[workspace]`
Error: command ["cargo", "build", "--config=net.git-fetch-with-cli=true", "--target=wasm32-unknown-unknown", "--release", "--message-format=json-render-diagnostics"] exited with code 101

[cloutiertyler]

Praise the heavens! Or in this case @bfops