Add ptvsd wheels and new DA support to remote debugging API

[kimadeline]

Related to #7001 (parent meta issue is #6017)

We expose debugger commands to other extensions since #3121, this API should be modified to support the new ptvsd wheels (port? host? wait for debugger?):

vscode-python/src/client/api.ts

Lines 36 to 49 in 9dec031

	export function buildApi(ready: Promise<any>) {
	return {
	// 'ready' will propogate the exception, but we must log it here first.
	ready: ready.catch((ex) => {
	traceError('Failure during activation.', ex);
	return Promise.reject(ex);
	}),
	debug: {
	async getRemoteLauncherCommand(host: string, port: number, waitUntilDebuggerAttaches: boolean = true): Promise<string[]> {
	return new RemoteDebuggerExternalLauncherScriptProvider().getLauncherArgs({ host, port, waitUntilDebuggerAttaches });
	}
	}
	};
	}

[karthiknadig]

Validated.