Move workspace list to using core api

[kushalmalani]

Description

Describe the purpose of this pull request.

Move workspace list to using core api

🎟 Issue(s)

Related #1260

🧪 Functional Testing

List the functional testing steps to confirm this feature or fix.

📸 Screenshots

Add screenshots to illustrate the validity of these changes.

📋 Checklist

• Rebased from the main (or release if patching) branch (before testing)
• Ran make test before taking out of draft
• Ran make lint before taking out of draft
• Added/updated applicable tests
• Tested against Astro-API (if necessary).
• Tested against Houston-API and Astronomer (if necessary).
• Communicated to/tagged owners of respective clients potentially impacted by these changes.
• Updated any related documentation

[codecov]

Codecov Report

Patch coverage: 95.45% and project coverage change: -0.02 ⚠️

Comparison is base (b857ffa) 87.64% compared to head (a259b5c) 87.63%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1259      +/-   ##
==========================================
- Coverage   87.64%   87.63%   -0.02%     
==========================================
  Files         110      110              
  Lines       12569    12558      -11     
==========================================
- Hits        11016    11005      -11     
- Misses        903      904       +1     
+ Partials      650      649       -1     

Impacted Files	Coverage Δ
astro-client/astro.go	100.00% <ø> (ø)
cloud/auth/auth.go	84.55% <90.90%> (-0.74%)	⬇️
cloud/workspace/workspace.go	83.04% <95.00%> (+1.26%)	⬆️
cloud/deployment/deployment.go	91.19% <100.00%> (ø)
cloud/deployment/fromfile/fromfile.go	98.80% <100.00%> (ø)
cmd/cloud/workspace.go	96.55% <100.00%> (ø)

☔ View full report in Codecov by Sentry.
📢 Do you have feedback about the report comment? Let us know in this issue.

[sunkickr]

This is great