[bug] Don't show "limit-info" div if API returns list for checks

[pandafy]

Describe the bug

If the logged-in user's RadiusGroup does not define any checks, then an empty box is shown where the user's usage is shown.

Steps To Reproduce
Steps to reproduce the behavior:

1. Setup WiFi Login Pages with OpenWISP RADIUS
2. Register with a user on WLP
3. In OpenWISP, change the Radius Group of the user to power-users.
4. Login to WLP with this user

Expected behavior
The empty div should not appear if the API endpoint returns an empty list for checks.

Add an automated test for this case.

Screenshots

[pandafy]

I suspect the error to be present here

openwisp-wifi-login-pages/client/components/status/status.js

Lines 343 to 371 in 8fc0221

	const response = await axios({
	method: "get",
	headers: {
	"content-type": "application/x-www-form-urlencoded",
	Authorization: `Bearer ${userData.auth_token}`,
	},
	url,
	});
	options.userChecks = response.data.checks;
	if (options.userChecks) {
	options.userChecks.forEach((check) => {
	if (check.value === String(check.result)) {
	isPlanExhausted = true;
	}
	});
	}
	if (planExhausted !== isPlanExhausted) {
	setPlanExhausted(isPlanExhausted);
	if (isPlanExhausted) {
	toast.info(t`PLAN_EXHAUSTED_TOAST`);
	}
	}
	if (response.data.plan) {
	options.userPlan = response.data.plan;
	}
	if (!showRadiusUsage) {
	options.showRadiusUsage = true;
	}
	this.setState(options);

[yours7himanshu]

@pandafy
This can be solved by checking condition if options.userChecks.length===0
Then we will return a word like item not present etc