[projmgr] Add reference to compile_commands.json file into cbuild.yml

[grasci-arm]

Address #2261
The new file type comp-db has been chosen for consistency with other file types in the schema: it's short and still reasonably intuitive.
The suggested additional node path is not being added because it would be superfluous in the current output structure where the cbuild.yml is already in the outdir (either default or custom), so output files are located alongside cbuild.yml itself.

[github-actions]

Test Results

    3 files     21 suites   14m 30s ⏱️
  449 tests   449 ✅ 0 💤 0 ❌
1 347 runs  1 347 ✅ 0 💤 0 ❌

Results for commit 4b52738.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 64.45%. Comparing base (708d541) to head (4b52738).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2365      +/-   ##
==========================================
+ Coverage   64.44%   64.45%   +0.01%     
==========================================
  Files         145      145              
  Lines       26018    26023       +5     
  Branches    15677    15681       +4     
==========================================
+ Hits        16766    16772       +6     
  Misses       7073     7073              
+ Partials     2179     2178       -1     

Flag	Coverage Δ
projmgr-cov	87.30% <100.00%> (+0.01%)	⬆️

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

Files with missing lines	Coverage Δ
tools/projmgr/src/ProjMgrCbuild.cpp	93.28% <100.00%> (+0.08%)	⬆️

... and 1 file with indirect coverage changes

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