Styling tweaks to inputs and Select (+ TimezoneSelect)

[emrysal]

What does this PR do?

This PR addresses inconsistencies in the design, does some cleanup, and design fixes - it's the result of a brief but in-depth investigation into react-select, tailwindcss & tailwindcss/forms, addressing the behaviour of form element focus:* classes.

• Removes the SetTimesModal & Scheduler file (which were the components that previously powered Availability)
• As part of this issue I opened RFC: Allow composition of the Select component. ndom91/react-timezone-select#64 - intended to reduce technical debt.
• Fixes this issue:
  
• Brand colors for form input focus (on app.cal.com)
  
• Fixes the styling of a few components that were out of sync like:
  
  

Fixes #2451

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)

[vercel]

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docs – ./apps/docs

🔍 Inspect: https://vercel.com/cal/docs/Ab94pARw96kbEPLF5hAP4ndPJWSC
✅ Preview: https://docs-git-feature-form-styling-cal.vercel.app

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calendso – ./apps/web

🔍 Inspect: https://vercel.com/cal/calendso/GgKTJPDsk3Vz7mN4zzneXLfaetHk
✅ Preview: https://calendso-git-feature-form-styling-cal.vercel.app

[Deployment for b502286 failed]

[PeerRich]

amazing! great for consistency