feat(app): add Skeleton component for second window

[koji]

Overview

add Skeleton component for second window

SkeletonForSlotDetail.mov

close AUTH-2558

Test Plan and Hands on Testing

• select a protocol
• click visualization button
• click a slot

Changelog

• add SkeletonForSlotDetail component and its test

Review requests

Risk assessment

low

[codecov]

Codecov Report

❌ Patch coverage is 95.23810% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 57.04%. Comparing base (a6d7686) to head (10ed09f).

Files with missing lines	Patch %	Lines
app/src/pages/Desktop/StepDetailViewer/index.tsx	0.00%	1 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##             edge   #20298       +/-   ##
===========================================
+ Coverage   25.78%   57.04%   +31.25%     
===========================================
  Files        3623     3624        +1     
  Lines      301823   301950      +127     
  Branches    42342    42588      +246     
===========================================
+ Hits        77827   172247    +94420     
+ Misses     223967   129476    -94491     
- Partials       29      227      +198     

Flag	Coverage Δ
app	46.26% <95.23%> (+45.10%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
...Desktop/StepDetailViewer/SkeletonForSlotDetail.tsx	100.00% <100.00%> (ø)
app/src/pages/Desktop/StepDetailViewer/index.tsx	3.44% <0.00%> (+3.44%)	⬆️

... and 1842 files with indirect coverage changes

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