feat(organizations): add theming/story for Mantine Modal TASK-1423

[pauloamorimbr]

🗒️ Checklist

1. run linter locally
2. update all related docs (API, README, inline, etc.), if any
3. draft PR with a title <type>(<scope>)<!>: <title> TASK-1234
4. tag PR: at least frontend or backend unless it's global
5. fill in the template below and delete template comments
6. review thyself: read the diff and repro the preview as written
7. open PR & confirm that CI passes
8. request reviewers, if needed
9. delete this section before merging

📣 Summary

Theming for Mantine's Modal was added to match Kobo's current KoboModal used for general purpose.

📖 Description

• Co-authored by @duvld

• We don't have a direct reference of an existing Kobo component, so we've came up a middle ground between the existing modals using though the application.
• We have added a Story with a big set of configurations to showcase the possibilities of the Modal
• The story also displays a way of
• We added a theme and style to the Modal component
• Title is using the default heading weight

👀 Preview steps

• Use storybook to check the visual of the component.