[86bye3tve][accordion] added compact mode prop

[msereniti]

Motivation and Context

For a long time our design has both compact and non compact accordions. Alongside react component were not supporting non compact accordion without hacks. This PR adds simple compact prop that is true by default for backward capability.

How has this been tested?

Manually and with VR.

Screenshots (if appropriate):

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 not work as expected).
• [ ] Nice improve.

Checklist:

• [x] My code follows the code style of this project.
• [x] I have updated the documentation accordingly or it's not required.
• [x] Unit tests are not broken.
• [x] I have added changelog note to corresponding CHANGELOG.md file with planned publish date.
• [x] I have added new unit tests on added of fixed functionality.

[j-mnizhek]

1. This accordion should be secondary not primary, since it usually uses less important place in the interface hierarchy.

2. Can we add margin-bottom: var(--intergalactic-spacing-05x) (or gap) by default for the ItemToggle for the primary accordion (as it was in the design)? The last child of course shouldn't have it.

[ilyabrower]

@msereniti

2. Can we add margin-bottom: var(--intergalactic-spacing-05x) (or gap) by default for the ItemToggle for the primary accordion (as it was in the design)? The last child of course shouldn't have it.

I've fixed it in https://github.com/semrush/intergalactic/pull/1468