feat: introduce css var for container position

[WalkingOS]

Closes #2202

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Issue

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• Tests for the changes have been added (for bug fixes / features)
• Docs have been reviewed and added / updated if needed (for bug fixes / features)

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Changes

Changes in this pull request:

Browsers

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Pull request type

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• Bugfix
• Feature
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no api changes)
• Build related changes
• Documentation content changes
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Does this introduce a breaking change?

• Yes
• No

Other information

[codecov-commenter]

Codecov Report

Attention: 64 lines in your changes are missing coverage. Please review.

Comparison is base (638977d) 92.61% compared to head (933a957) 95.97%.
Report is 80 commits behind head on master.

Files	Patch %	Lines
...nents/core/common-behaviors/slot-child-observer.ts	93.33%	5 Missing ⚠️
src/components/core/dom/breakpoint.ts	42.85%	4 Missing ⚠️
src/components/autocomplete/autocomplete.ts	70.00%	3 Missing ⚠️
src/components/card/card-action/card-action.ts	70.00%	3 Missing ⚠️
src/components/core/dom/dataset.ts	25.00%	3 Missing ⚠️
src/components/core/dom/host-context.ts	40.00%	3 Missing ⚠️
src/components/header/header/header.ts	50.00%	3 Missing ⚠️
src/components/image/image.ts	93.33%	3 Missing ⚠️
src/components/tooltip/tooltip/tooltip.ts	25.00%	3 Missing ⚠️
src/components/calendar/calendar.ts	86.66%	2 Missing ⚠️
... and 26 more

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Additional details and impacted files

@@            Coverage Diff             @@
##           master    #2229      +/-   ##
==========================================
+ Coverage   92.61%   95.97%   +3.36%     
==========================================
  Files          53      330     +277     
  Lines        2409    39158   +36749     
  Branches      254     2181    +1927     
==========================================
+ Hits         2231    37581   +35350     
- Misses        176     1532    +1356     
- Partials        2       45      +43     

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[jeripeierSBB]

LGTM