chore: update dependencies and enhance connectivity service

- Added `connectivity_plus` dependency to manage network connectivity status.
- Updated `pubspec.yaml` to include the new dependency version.
- Enhanced `ConnectivityService` to utilize `connectivity_plus` for improved connectivity monitoring and handling.
- Refactored connectivity checks and state management for better performance and reliability.

pubspec.lock

@@ -225,6 +225,22 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "1.19.1"
+  connectivity_plus:
+    dependency: "direct main"
+    description:
+      name: connectivity_plus
+      sha256: "33bae12a398f841c6cda09d1064212957265869104c478e5ad51e2fb26c3973c"
+      url: "https://pub.dev"
+    source: hosted
+    version: "7.0.0"
+  connectivity_plus_platform_interface:
+    dependency: transitive
+    description:
+      name: connectivity_plus_platform_interface
+      sha256: "42657c1715d48b167930d5f34d00222ac100475f73d10162ddf43e714932f204"
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.0.1"
   convert:
     dependency: transitive
     description:
@@ -917,6 +933,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "1.0.0"
+  nm:
+    dependency: transitive
+    description:
+      name: nm
+      sha256: "2c9aae4127bdc8993206464fcc063611e0e36e72018696cd9631023a31b24254"
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.5.0"
   node_preamble:
     dependency: transitive
     description: