UI: Update Base Font Size to 14px

[fmontes]

Task description

As a dotCMS user, I want the base font size to be reduced to 14px while keeping the spacings based on 16px to improve readability and design consistency across the website.

### Acceptance Criteria
- [ ] The base font size in the UI should be 14px.
- [ ] Spacings between elements should remain consistent at 16px.
- [ ] All text should be legible and easily readable at the new font size.
- [ ] This change should NOT affect native a11y of the browser

External Links

N/A

Assumptions & Initiation Needs

• Assumption: The current font size is set at 16px.
• Initiation: Access to the dotCMS backend to make the necessary CSS changes.
• We need to check ALL pages to make sure nothing breaks

Quality Assurance Notes & Workarounds

• QA should check all pages to ensure the new font size is consistent and does not cause any readability issues.
• In case of any spacing issues, the QA team should provide feedback for adjustments.