fix: repair TileLayer.tileBounds

[josxha]

This pull request fixes the TileLayer.tileBounds property (issue #1710).
It was such a small bug that I overlooked it multiple times. 🥲

Additionally it fixes a typo and removes a duplicate variable.

See a minimal example here

import 'package:flutter/material.dart';
import 'package:flutter_map/flutter_map.dart';
import 'package:latlong2/latlong.dart';

void main() => runApp(const MyApp());

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return const MaterialApp(
        home: TileBoundsTest(),
    );
  }
}

class TileBoundsTest extends StatelessWidget {
  const TileBoundsTest({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Tile bounds test')),
      body: Padding(
        padding: const EdgeInsets.all(8),
        child: Column(
          children: [
            Flexible(
              child: FlutterMap(
                options: const MapOptions(
                  initialCenter: LatLng(53.189206, -1.821145),
                  initialZoom: 5,
                ),
                children: [
                  TileLayer(
                    urlTemplate:
                    'https://tile.openstreetmap.org/{z}/{x}/{y}.png',
                    userAgentPackageName: 'dev.fleaflet.flutter_map.example',
                    tileBounds: LatLngBounds(
                      const LatLng(58.429514, -13.084017),
                      const LatLng(50.221127, 1.802305),
                    ), // uk bounds
                  ),
                ],
              ),
            ),
          ],
        ),
      ),
    );
  }
}

[JaffaKetchup]

LGTM! My mistake on the docs spelling - can never spell "recieve" correctly :D