feat: overlay

[wainola]

Description

Implenentation of loader overlay

Related Issue Or Context

Closes: #66

How Has This Been Tested? Testing details.

Types of changes

• [ ] Bug fix (non-breaking change which fixes an issue)
• [x] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)
• [ ] Documentation

Checklist:

• [ ] I have commented my code, particularly in hard-to-understand areas.
• [ ] I have ensured that all acceptance criteria (or expected behavior) from issue are met
• [ ] I have updated the documentation locally and in sygma-docs.
• [ ] I have added tests to cover my changes.
• [ ] I have ensured that all the checks are passing and green, I've signed the CLA bot

[wainola]

@mpetrunic contrary to what I thought, since we are handling the state of the opening and close of the overlay in the widget, it doens't make sense to have event propagation from the overlay itself to signal change of the loading state. Because of that implementation of the component is pretty straigthforward. Possible improvement is to move the spiner itself to a separate component, so we can use that for the button. Wdyt?

[mpetrunic]

ugh, I think you need to fix those conflicts 🙈