[EuiSuperDatePicker] Fix dates overflowing out of the delimited inputs

[cee-chen]

Summary

Partially addresses https://github.com/elastic/kibana/issues/197892

Before	After

• bonus reduction of now input widths, more closely matching how EuiSuperDatePicker used to behave pre-Emotion conversion.

QA

• Go to https://eui.elastic.co/pr_8109/storybook/?path=/story/forms-euisuperdatepicker-euisuperdatepicker--playground&globals=viewport:mobile1
• Click the pretty duration and then the start or end input
• [x] Switch to an Absolute date and confirm that the longer date format does not overflow outside the total input width

General checklist

• Browser QA
  • [x] Checked in mobile
  • [x] Checked in Chrome, Safari, Edge, and Firefox ~- [ ] Checked in both light and dark modes~ ~- [ ] Checked for accessibility including keyboard-only and screenreader modes~
• Docs site QA - N/A
• Code quality checklist ~- [ ] Added or updated jest and cypress tests~
  • [x] Updated visual regression tests
• Release checklist
  • [x] A changelog entry exists and is marked appropriately. ~- [ ] If applicable, added the breaking change issue label (and filled out the breaking change checklist)~
• Designer checklist - N/A

[kibanamachine]

Preview staging links for this PR:

• Docs site: https://eui.elastic.co/pr_8109/
• Storybook: https://eui.elastic.co/pr_8109/storybook
• New docs: https://eui.elastic.co/pr_8109/new-docs

[elasticmachine]

:green_heart: Build Succeeded

• Buildkite Build
• Commit: ae891a1793b543bb8af1fd8b7f8112789635abe4

History

• :green_heart: Build #2991 succeeded eed9887db4efa934e8805b24f040729e5c74e32e