Use the debug adapter from cdt-gdb-vscode/cdt-gdb-adapter

This patch swaps the debug adapter we use from code-debug to
cdt-gdb-vscode.  The adapter was built using

    npm install && npm run build && npm pack

and hosted as a release at [1].

The file cpp-debug-configuration-schema.json seems unused, so I've
removed it.  The schema for configurations comes from the package.json
of the debug adapter/extension anyway.

[1] https://github.com/theia-ide/cdt-gdb-vscode

Signed-off-by: Simon Marchi <simon.marchi@ericsson.com>

packages/cpp-debug/package.json

@@ -42,6 +42,6 @@
       "backend": "lib/node/cpp-debug-backend-module"
   }],
   "adapters": {
-    "code-debug": "https://github.com/marechal-p/code-debug/releases/download/v0.22.0/code-debug.tar.gz"
+    "cdt-gdb-vscode": "https://github.com/theia-ide/cdt-gdb-vscode/releases/download/v0.0.4/cdt-gdb-vscode-0.0.4.tgz"
   }
 }

packages/cpp-debug/src/node/cpp-debug-contribution.ts

@@ -21,7 +21,7 @@ import { join } from 'path';
 import * as Ajv from 'ajv';
 
 const adapterName = 'gdb';
-const adapterPath = join(__dirname, '../../adapters/code-debug');
+const adapterPath = join(__dirname, '../../adapters/cdt-gdb-vscode/package');
 
 // Load schema from package.json
 const packageJson = require(join(adapterPath, 'package.json'));