Add handling of no internet connection messages

PART OF GTC OPEN SOURCE INTIATIVE

The flutter-bond repo currently does not handle any internet connection messages. This can lead to unexpected behavior, such as errors or blank screens.

For example, if a user tries to access a feature that requires an internet connection, but they do not have an internet connection, the app will crash or show a blank screen.

**Proposed Solution**

We should add a new feature to handle no internet connection messages. This feature could do the following:

1. Check the internet connection before making any requests.
2. Display a letter to the user if there is no internet connection.
3. Allow the user to retry the request when the internet connection is restored.

**Benefits**

This feature would improve the usability of the flutter-bond repo and make it more user-friendly. It would also prevent users from experiencing unexpected behavior when they do not have an internet connection.

**Steps to Reproduce**

1. Open the flutter-bond app.
2. Try to use a feature that requires an internet connection.
3. You will see an error message or a blank screen or just loading.

**Expected Behavior**

When the user tries to use a feature that requires an internet connection and there is no internet connection, the app should display a message to the user and allow them to retry the request when the internet connection is restored.

**Actual Behavior**

When the user tries to use a feature that requires an internet connection and there is no internet connection, the app will show an error message or a blank screen.

**Additional Details**

- Severity: Is it a critical issue that prevents the app from working at all, or is it a less serious issue that only affects certain features?
- Steps to Reproduce: What steps can a user take to reproduce the issue?
- Expected Behavior: What should happen when the user tries to use the app when there is no internet connection?
- Actual Behavior: What actually happens when the user tries to use the app in a situation where there is no internet connection?

_Thanks for your consideration!_