feat: add workspaceDir and use it for presets auto generated dir

[danielroe]

🔗 Linked issue

resolves #149

❓ Type of change

• 📖 Documentation (updates to the documentation or readme)
• 🐞 Bug fix (a non-breaking change that fixes an issue)
• 👌 Enhancement (improving an existing functionality like performance)
• ✨ New feature (a non-breaking change that adds functionality)
• ⚠️ Breaking change (fix or feature that would cause existing functionality to change)

📚 Description

This is an initial implementation of workspaceDir and migrating presets that have 'magic folders' (vercel, netlify + stormkit) to use this.

📝 Checklist

• I have linked an issue or discussion.
• I have updated the documentation accordingly.

[codecov]

Codecov Report

Merging #481 (58e2d60) into main (c902104) will decrease coverage by 0.05%.
The diff coverage is 40.00%.

@@            Coverage Diff             @@
##             main     #481      +/-   ##
==========================================
- Coverage   63.34%   63.29%   -0.06%     
==========================================
  Files          54       54              
  Lines        3615     3618       +3     
  Branches      381      380       -1     
==========================================
  Hits         2290     2290              
- Misses       1314     1316       +2     
- Partials       11       12       +1     

Impacted Files	Coverage Δ
src/types/nitro.ts	100.00% <ø> (ø)
src/presets/netlify.ts	24.41% <25.00%> (ø)
src/options.ts	49.32% <33.33%> (-0.68%)	⬇️
src/presets/vercel.ts	77.47% <50.00%> (ø)
src/presets/stormkit.ts	100.00% <100.00%> (ø)

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.