Added content for Pub Sub API demo

[pozil]

This PR adds content for an optional Pub Sub API demo.
The merge will be aligned with the GA of the Pub Sub API scheduled on June 30.

[codecov]

Codecov Report

Merging #419 (ba141d3) into main (c3c8e56) will increase coverage by 10.91%.
The diff coverage is 93.10%.

@@             Coverage Diff             @@
##             main     #419       +/-   ##
===========================================
+ Coverage   72.50%   83.41%   +10.91%     
===========================================
  Files          21       21               
  Lines         360      410       +50     
  Branches       26       45       +19     
===========================================
+ Hits          261      342       +81     
+ Misses         97       66       -31     
  Partials        2        2               

Flag	Coverage Δ
Apex	100.00% <ø> (ø)
LWC	80.79% <93.10%> (+13.35%)	⬆️

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

Impacted Files	Coverage Δ
...ain/default/lwc/orderStatusPath/orderStatusPath.js	92.94% <92.94%> (ø)
force-app/main/default/lwc/ldsUtils/ldsUtils.js	100.00% <100.00%> (ø)
...efault/lwc/errorPanel/__tests__/errorPanel.test.js

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update c3c8e56...ba141d3. Read the comment docs.