Refactor release block

What does this MR do?

This MR breaks up the release block component into subcomponents, leaving the parent to focus only on rendering. The main goal is to make the component smaller and to create a situation where it does not grow out of control in the future. As more items are added to the release block, it is now natural to construct them as subcomponents and keep the parent in charge of conditionals and scrolling.

Most of the code has not changed and has only been moved. The main exception was to render the author with the new gl-sprintf component, which is an i18n win. Woo-hoo!

Screenshots

Does this MR meet the acceptance criteria?

Conformity

• Code review guidelines
• Merge request performance guidelines
• Style guides

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.