[Storybook] Add stories for more components (letters R-S) - Part 1

[mgadewoll]

Summary

Relates to #7482.

This PR adds more stories for components with the letter P:

• EuiResizableContainer
• EuiResizablePanel
• EuiShowFor
• EuiSearchBar
• EuiSearchFilters
• EuiSpacer
• EuiStat

QA

• [ ] Confirm that the prop controls for all the below stories provide relevant controls and that those controls work as expected:

• https://eui.elastic.co/pr_7687/storybook/index.html?path=/story/layout-euiresizablecontainer-euiresizablecontainer--playground

• https://eui.elastic.co/pr_7687/storybook/index.html?path=/story/layout-euiresizablecontainer-euiresizablepanel--playground

• https://eui.elastic.co/pr_7687/storybook/index.html?path=/story/utilities-euishowfor--playground

• https://eui.elastic.co/pr_7687/storybook/index.html?path=/story/forms-euisearchbar-euisearchbar--playground

• https://eui.elastic.co/pr_7687/storybook/index.html?path=/story/forms-euisearchbar-euisearchbarfilters--playground

• https://eui.elastic.co/pr_7687/storybook/index.html?path=/story/layout-euispacer--playground

• https://eui.elastic.co/pr_7687/storybook/index.html?path=/story/display-euistat--playground

[kibanamachine]

Preview staging links for this PR:

• Docs site: https://eui.elastic.co/pr_7687/
• Storybook: https://eui.elastic.co/pr_7687/storybook

[elasticmachine]

:green_heart: Build Succeeded

• Buildkite Build
• Commit: 6ca6c207e65fb7ea08368f95c31ca6be2ee34b8d

History

• :green_heart: Build #1834 succeeded 14b423b5ec0cf2a72e7f8606e0423d757eabe6b0
• :green_heart: Build #1829 succeeded 48ef4f76bfea0ff94abed696248f9e9333140b86
• :green_heart: Build #1765 succeeded edbc7e68634a2ad550075fe50bf2f6fc8da056e2
• :green_heart: Build #1762 succeeded 4d2398d8e4c1f4d7ee8e3b370d51f02dc2015bcc