VSCode should look for fpp_lsp_server in `<projRoot>/fprime-venv`

[thomas-bc]

Per VSCode docs:

When you open a .fpp file, the extension locates fpp_lsp_server automatically:

• the fpp.serverPath setting, if you set it explicitly;
• the workspace Python venv — discovered via the Python extension or by scanning for a .venv/venv/env directory (override with fpp.pythonVenv);
• fpp_lsp_server on your PATH.

Often VSCode will activate fprime-venv so I'm assuming it'll find it on the path, but in some cases that may not be the case. Since we already look for .venv/venv/env, and fprime kinda has this fprime-venv "standard", would be good to look there too

[Kronos3]

Poor documentation but it does do this already:

fpp-tools/editors/code/src/serverPath.ts

Lines 170 to 177 in e9d1ff9

	// `fprime-venv` is the canonical venv name for F Prime projects; check it first.
	for (const name of ['fprime-venv', '.venv', 'venv', 'env']) {
	const root = path.join(folder.uri.fsPath, name);
	if (await isVenv(root)) {
	return await venvInfo(root);
	}
	}
	return undefined;

I'm interested to hear about cases where the LSP is not detected since I have not seen this