Polish blueprint mode of pre-chat starter prompts

[compulim]

Changelog Entry

Added

• Added blueprint of starter prompts in the Fluent theme, in PR #5270, #5276 and #5279, by @OEvgeny and @compulim

Description

This is continuation of #5276.

Polishes the blueprint of starter prompts and supports RTL in animation.

Specific Changes

• Corrected gaps between skeleton of title and subtitle
• Updated animation to support RTL
• Also fixed flakiness test related to upload
  • After upload and send, should wait for outgoing activities to be sent

• I have added tests and executed them locally
• I have updated CHANGELOG.md
• I have updated documentation

Review Checklist

This section is for contributors to review your work.

• Accessibility reviewed (tab order, content readability, alt text, color contrast)
• Browser and platform compatibilities reviewed
• CSS styles reviewed (minimal rules, no z-index)
• Documents reviewed (docs, samples, live demo)
• Internationalization reviewed (strings, unit formatting)
• package.json and package-lock.json reviewed
• Security reviewed (no data URIs, check for nonce leak)
• Tests reviewed (coverage, legitimacy)

[OEvgeny]

After some thinking... We should adjust:

  &[aria-disabled='true'],
  &:empty {
    cursor: default;
    row-gap: 14px;
  }

to either:

  &[aria-disabled='true'],
  &:empty {
    cursor: default;
  }
  &:empty {
    row-gap: 14px;
  }

Or update the row-gap for the whole card UX