[TASK-884] Implement reusable export button

[pauloamorimbr]

Task

Checklist

1. If you've added code that should be tested, add tests
2. If you've changed APIs, update (or create!) the documentation
3. Ensure the tests pass
4. Run ./python-format.sh to make sure that your code lints and that you've followed our coding style
5. Write a title and, if necessary, a description of your work suitable for publishing in our release notes
6. Mention any related issues in this repository (as #ISSUE) and in other repositories (as kobotoolbox/other#ISSUE)
7. Open an issue in the docs if there are UI/UX changes
8. Create a testing plan for the reviewer and add it to the Testing section

Description

This PR implements the functionality for the export button.

• Actual export function is mocked and will not generate any data
• The mocked results now have a 50% chance of failure for testing purposes

Notes

• A new "ExportButton" component was created.
• It receives an async function to be called when clicked
• If the export process is successfully started it will display a message to the user
• If an error occurs, alertify is used to display an error message

Testing

• Access the project settings
• Be sure to have the ?ff_activityLogsEnabled=true feature flag on
• Access the Activity sub view
• Click the export button some times.
• It should display the successful or error message depending on the (random) result.

[notion-workspace]

Add reusable export button

[notion-workspace]

Add reusable export button