fix(Tab): indicator width calculations

[arpitBhalla]

Motivation

Fixes # (issue)

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

• Jest Unit Test
• Checked with example app

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation using yarn docs-build-api
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules

Additional context

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[codecov]

Codecov Report

Merging #3807 (396845b) into next (6ea6a97) will increase coverage by 0.62%.
The diff coverage is 83.78%.

❗ Current head 396845b differs from pull request most recent head 1a3c441. Consider uploading reports for the commit 1a3c441 to get more accurate results

@@            Coverage Diff             @@
##             next    #3807      +/-   ##
==========================================
+ Coverage   79.39%   80.02%   +0.62%     
==========================================
  Files          87       87              
  Lines        1820     1822       +2     
  Branches      810      811       +1     
==========================================
+ Hits         1445     1458      +13     
+ Misses        370      359      -11     
  Partials        5        5              

Impacted Files	Coverage Δ
packages/base/src/Avatar/index.tsx	100.00% <ø> (ø)
packages/base/src/Tab/Tab.Item.tsx	95.45% <ø> (ø)
packages/base/src/Tab/Tab.tsx	64.51% <53.84%> (+4.19%)	⬆️
packages/base/src/Avatar/Avatar.tsx	100.00% <100.00%> (+2.77%)	⬆️
...ages/base/src/CheckBox/components/CheckBoxIcon.tsx	100.00% <100.00%> (ø)
packages/base/src/Divider/Divider.tsx	92.30% <100.00%> (ø)
packages/base/src/Header/Header.tsx	96.55% <100.00%> (+0.39%)	⬆️
packages/base/src/Icon/Icon.tsx	100.00% <100.00%> (ø)
packages/base/src/Input/Input.tsx	66.66% <100.00%> (+0.87%)	⬆️
packages/themed/src/config/ThemeProvider.tsx	76.59% <100.00%> (+12.76%)	⬆️

... and 1 file with indirect coverage changes

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[mkozmelj]

Any progress on this MR?