refactor(app): replace 12px with a new spacing

[koji]

Overview

replace 12px with a new spacing
padding and margin that use 0.75rem -> SPACING.spacing12

Test Plan

not required

Changelog

• 0.75rem -> SPACING.spacing12
• update stories for Spacing

Review requests

Risk assessment

low

[ewagoner]

Approved pending fixing the two missing imports.

[codecov]

Codecov Report

Merging #12688 (e832f28) into edge (63b3333) will increase coverage by 0.02%.
The diff coverage is 80.00%.

@@            Coverage Diff             @@
##             edge   #12688      +/-   ##
==========================================
+ Coverage   73.50%   73.53%   +0.02%     
==========================================
  Files        2281     2282       +1     
  Lines       62665    62834     +169     
  Branches     6706     6780      +74     
==========================================
+ Hits        46065    46204     +139     
- Misses      14999    15011      +12     
- Partials     1601     1619      +18     

Flag	Coverage Δ
app	72.05% <80.00%> (+0.09%)	⬆️

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

Impacted Files	Coverage Δ
app/src/App/Navbar.tsx	90.90% <ø> (ø)
app/src/atoms/InlineNotification/index.tsx	70.00% <ø> (ø)
app/src/atoms/MenuList/MenuItem.tsx	100.00% <ø> (ø)
app/src/atoms/SelectField/Select.tsx	47.61% <ø> (ø)
app/src/atoms/Toast/index.tsx	77.14% <0.00%> (ø)
app/src/atoms/buttons/FloatingActionButton.tsx	100.00% <ø> (ø)
...rc/molecules/WizardRequiredEquipmentList/index.tsx	95.00% <ø> (ø)
app/src/organisms/AnalyticsSettingsModal/index.tsx	33.33% <ø> (ø)
...ckCalibration/ResultsSummary/CalibrationResult.tsx	100.00% <ø> (ø)
...s/CheckCalibration/ResultsSummary/RenderResult.tsx	100.00% <ø> (ø)
... and 28 more

... and 3 files with indirect coverage changes