[projmgr] Improve errors/warnings around component validation (#1384)

[grasci-arm]

Related to ARM-software/vscode-cmsis-csolution#456

• Refine error message's text
• Skip redundant error message for unresolved component
• Skip further validation warnings as long as there are unresolved components

[github-actions]

Test Results

    3 files     21 suites   14m 27s ⏱️
  435 tests   435 ✅ 0 💤 0 ❌
1 305 runs  1 305 ✅ 0 💤 0 ❌

Results for commit 985a545.

[codecov]

Codecov Report

❌ Patch coverage is 42.85714% with 8 lines in your changes missing coverage. Please review.
✅ Project coverage is 66.36%. Comparing base (9b0ba48) to head (985a545).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
tools/projmgr/test/src/ProjMgrUnitTests.cpp	16.66%	0 Missing and 5 partials ⚠️
tools/projmgr/test/src/ProjMgrWorkerUnitTests.cpp	0.00%	0 Missing and 2 partials ⚠️
tools/projmgr/test/src/ProjMgrRpcTests.cpp	0.00%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2319      +/-   ##
==========================================
- Coverage   66.37%   66.36%   -0.02%     
==========================================
  Files         181      181              
  Lines       36674    36670       -4     
  Branches    22807    22803       -4     
==========================================
- Hits        24344    24336       -8     
- Misses       7625     7628       +3     
- Partials     4705     4706       +1     

Flag	Coverage Δ
projmgr-cov	80.28% <42.85%> (-0.04%)	⬇️

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

Files with missing lines	Coverage Δ
tools/projmgr/include/ProjMgrWorker.h	75.86% <ø> (ø)
tools/projmgr/src/ProjMgrWorker.cpp	88.05% <100.00%> (-0.02%)	⬇️
tools/projmgr/test/src/ProjMgrRpcTests.cpp	52.90% <0.00%> (ø)
tools/projmgr/test/src/ProjMgrWorkerUnitTests.cpp	65.56% <0.00%> (ø)
tools/projmgr/test/src/ProjMgrUnitTests.cpp	79.06% <16.66%> (ø)

... and 1 file with indirect coverage changes

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