[projmgr] Add list debuggers command

[grasci-arm]

Address #2109

list debuggers prints a plain list of debugger adapter names from debug-adapters.yml file, for instance:

CMSIS-DAP@pyOCD
CMSIS-DAP@Arm-Debugger

list debuggers --verbose prints additionally their aliases, for example:

CMSIS-DAP@pyOCD
  CMSIS-DAP
  DAP-Link
CMSIS-DAP@Arm-Debugger
  CMSIS-DAP@armdbg

[github-actions]

Test Results

    3 files     21 suites   13m 37s ⏱️
  409 tests   409 ✅ 0 💤 0 ❌
1 227 runs  1 227 ✅ 0 💤 0 ❌

Results for commit 8770aa8.

[codecov]

Codecov Report

Attention: Patch coverage is 73.80952% with 11 lines in your changes missing coverage. Please review.

Project coverage is 66.59%. Comparing base (a17de20) to head (8770aa8).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
tools/projmgr/src/ProjMgr.cpp	72.00%	4 Missing and 3 partials ⚠️
tools/projmgr/test/src/ProjMgrUnitTests.cpp	76.47%	0 Missing and 4 partials ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2158   +/-   ##
=======================================
  Coverage   66.58%   66.59%           
=======================================
  Files         181      181           
  Lines       37823    37865   +42     
  Branches    22052    22077   +25     
=======================================
+ Hits        25186    25217   +31     
- Misses       8060     8064    +4     
- Partials     4577     4584    +7     

Flag	Coverage Δ
projmgr-cov	81.26% <73.80%> (-0.03%)	⬇️

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Files with missing lines	Coverage Δ
tools/projmgr/include/ProjMgr.h	100.00% <ø> (ø)
tools/projmgr/test/src/ProjMgrUnitTests.cpp	80.40% <76.47%> (-0.02%)	⬇️
tools/projmgr/src/ProjMgr.cpp	80.20% <72.00%> (-0.27%)	⬇️

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