fix: Dashboard editable title weird behavior when adding spaces

[kgabryje]

SUMMARY

When user added trailing spaces to dashboard's title in edit mode, the input's width wasn't updating as expected, causing weird behaviour (like in the recording). Adding white-space: pre style causes the trailing spaces to not be ignored by resize observers.

BEFORE/AFTER SCREENSHOTS OR ANIMATED GIF

Before:

Screen.Recording.2024-07-23.at.14.19.26.mov

After:

Screen.Recording.2024-07-23.at.14.11.48.mov

TESTING INSTRUCTIONS

1. Open a dashboard in edit mode
2. Add some trailing spaces to the suffix
3. Verify that the input scales as expected

ADDITIONAL INFORMATION

• Has associated issue:
• Required feature flags:
• Changes UI
• Includes DB Migration (follow approval process in SIP-59)
  • Migration is atomic, supports rollback & is backwards-compatible
  • Confirm DB migration upgrade and downgrade tested
  • Runtime estimates and downtime expectations provided
• Introduces new feature or API
• Removes existing feature or API

[sadpandajoe]

@supersetbot label 4.1