Add IOC ibek url macro and macro validation

[OCopping]

The "MORE" button on embedded screens doesn't currently point to the ibek screens. This PR adds a new macro to all newly generated embedded screens to link to these.
It also adds macro validation.

Links to #186, but doesn't fix it.

[codecov]

Codecov Report

❌ Patch coverage is 93.33333% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 89.55%. Comparing base (a4550a3) to head (c4db300).
⚠️ Report is 4 commits behind head on main.

Files with missing lines	Patch %	Lines
src/techui_builder/validator.py	90.90%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #187      +/-   ##
==========================================
+ Coverage   89.48%   89.55%   +0.06%     
==========================================
  Files           9        9              
  Lines         685      699      +14     
==========================================
+ Hits          613      626      +13     
- Misses         72       73       +1     

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