Used MockInstallation consistently instead of create_autospec(Installation)

[nkvuong]

Changes

• Replaced all usage of create_autospec(Installation) with MockInstallation
• One final usage requires added content assertion for assert_file_uploaded and assert_file_dbfs_uploaded in MockInstallation blueprint#101

Tests

• manually tested
• verified on staging environment (screenshot attached)

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 90.18%. Comparing base (1350995) to head (55dc8cd).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1649   +/-   ##
=======================================
  Coverage   90.18%   90.18%           
=======================================
  Files          86       86           
  Lines       10584    10584           
  Branches     1865     1865           
=======================================
  Hits         9545     9545           
  Misses        679      679           
  Partials      360      360           

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[github-actions]

✅ 160/160 passed, 25 skipped, 2h29m54s total

_{Running from acceptance #3039}

[JCZuurmond]

💯