feat: use @alma-cdk/construct-library custom Projen project type

[aripalo]

• Bump major version to 3 (forces explicit upgrade from users)
• src-files have only formatting changes (that come from updating Projen tooling)
• Use of @alma-cdk/construct-library custom Projen project type to define reasonable defaults for the project
• Upgraded dependencies

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 100.00%. Comparing base (53de62a) to head (9cc8563).
⚠️ Report is 6 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff            @@
##              main       #44   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files            3         3           
  Lines          235       254   +19     
  Branches         9         9           
=========================================
+ Hits           235       254   +19     

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[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud